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Improving the Accuracy of Civil Damage Awards With Claim Aggregation
CitationBavli, Hillel J. 2017. Improving the Accuracy of Civil Damage Awards With Claim Aggregation. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences.
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ImprovingtheAccuracyofCivilDamageAwardswithClaimAggregation
Adissertationpresentedby
HillelJ.Bavlito
TheadhocCommitteeforthePh.D.PrograminStatisticsinLawandGovernment
inpartialfulfillmentoftherequirements
forthedegreeof
DoctorofPhilosophy
inthesubjectof
StatisticsinLawandGovernment
HarvardUniversity
Cambridge,Massachusetts
January2017
©2016HillelJ.BavliAllrightsreserved.
iii
DissertationAdvisor:ProfessorDonaldRubin HillelJ.Bavli
ImprovingtheAccuracyofCivilDamageAwardswithClaimAggregation
Abstract
Alegalproceedingcanbeunderstoodasanestimationproblem,wherethequality
ofthelegaloutcomedependsontheinformationusedtoadjudicateit.ThisPh.D.
Dissertationisacompilationoffivepapersthatexamineasetofmethodsforimprovingthe
informationusedtoadjudicatelegaloutcomesinthecontextofcivilclaimsfordamages.
Thepapersanalyzethepossibilityofimprovingcivildamageawardsbyaggregating
informationacrossdifferentclaims—first,acrossclaimsintheclass-actioncontext,and
second,acrossclaimsinaltogetherseparatecasesovertime.Thepapersexaminesuch
methodsstatistically,analyzingwhether,andunderwhatconditions,aggregating
informationregardingdamageawardsorfactsinseparateclaimswouldimprovethe
qualityofawards.Andtheyexaminesuchmethodslegally,assessingwhether,andunder
whatconditions,suchmethodsarepermissibleunderevidentiary,procedural,and
constitutionalframeworks.Thefinalpaperreportsandinterpretsresultsfromafactorial
experimentdesignedtotestcertainconclusionsrelatingtothesemethods.Insummary,the
papersdemonstratethatthemethodsdiscussedarecapableofimprovingdamageawards
substantially,andaregenerallypermissibleunderthelaw.
iv
TABLEOFCONTENTSINTRODUCTION 1
I.AGGREGATINGFORACCURACY:ACLOSERLOOKATSAMPLINGANDACCURACYINCLASSACTIONLITIGATION 4
II.SAMPLINGANDRELIABILITYINCLASSACTIONLITIGATION 49
III.THELOGICOFCOMPARABLE-CASEGUIDANCEINTHEDETERMINATIONOFAWARDSFORPAINANDSUFFERINGANDPUNITIVEDAMAGES 68
IV.SHRINKAGEESTIMATIONINTHEADJUDICATIONOFCIVILDAMAGECLAIMS 114
V.GUIDINGJURORSWITHPRIOR-AWARDINFORMATION:ARANDOMIZEDEXPERIMENT 152
1
Introduction
Alegalproceedingcanbeunderstoodasanestimationproblem.Imaginethatthere
issome“correct”outcome,oratleastarangeof“acceptable”outcomes,thatreflectsthe
policyobjectives(suchasfairnessordeterrence)underlyingthesubstantivelawgoverning
thecaseathand,aswellasthe“true”stateoftheworld,includingthelawandthe
circumstancesofthecase.Aproceeding,suchasahearingortrial,isnecessary,because
thereisimperfectinformationregardingthelawandthecircumstancesofthecase.The
proceedinggeneratesinformationthrough,forexample,argumentationandthe
presentationofevidence.Andbasedonthislimitedinformation,itproducesalegal
outcome—anestimateofthe“correct”outcome.1Thequalityofthelegaloutcome,
therefore,dependsontheinformationusedtoadjudicateit.
ThisPh.D.Dissertationisacompilationoffivepapers,correspondingtothefive
sectionsbelow,thatexamineasetofmethodsforimprovingtheinformationusedto
adjudicatelegaloutcomesinthecontextofcivilclaimsfordamages.Specifically,thepapers
hereinanalyzethepossibilityofimprovingcivildamageawardsbyaggregating
informationacrossseparateclaims.Suchmethodsgiverisetoarangeofstatisticaland
legalquestions.Statistically,thepapersexaminewhether,andunderwhatconditions,
aggregatinginformationregardingdamageawardsorfactsinseparateclaimswould
improvethequalityofawards.Legally,thepapersassesswhether,andunderwhat
1Seeinfra§I.
2
conditions,suchmethodsarepermissibleunderevidentiary,procedural,andconstitutional
frameworks.
Thefirstpaper,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyin
ClassActionLitigation(publishedinLaw,Probability&Risk),2discussesaggregation
proceduresintheclassactioncontext,wherebydamageawardsforclassclaimsare
extrapolatedfromasmallsampleofrepresentativeadjudications.Itexaminesthe
conditionsunderwhichsuchprocedureswouldimprovethequalityofawards,aswellas
relevantlegalconsiderations.Thesecondpaper,SamplingandReliabilityinClassAction
Litigation(publishedinCardozoLawReviewdenovo),3isashortpaperthatexplainsthe
conclusionsinthefirstpaperinnon-mathematicaltermsandextendstheminlightofthe
recentSupremeCourtdecisioninTysonFoods,Inc.v.Bouaphakeo.4
Thethirdpaper,TheLogicofComparable-CaseGuidanceintheDeterminationof
AwardsforPainandSufferingandPunitiveDamages(forthcomingintheUniversityof
CincinnatiLawReview),5analyzesasetofaggregationmethodsapplicableinthe
individual-claimcontext.Whereasthefirstsetofaggregationmethodsappliestotheclass
actioncontext,andthereforeinvolvesapredefinedclassofclaimsarisingfromcommon
factsandissues,thesemethodsinvolvethesharingofinformationacrossaltogether
separatecasesovertime.Specifically,thepaperexaminestheuseof“comparable-case
2HillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation,14LAW,PROBABILITY&RISK67(2015).
3HillelJ.Bavli,SamplingandReliabilityinClassActionLitigation,2016CARD.L.REV.DENOVO207(2016).
4136S.Ct.1036(2016).
5HillelJ.Bavli,TheLogicofComparable-CaseGuidanceintheDeterminationofAwardsforPainandSufferingandPunitiveDamages,U.CIN.L.REV.(forthcoming,2017).
3
guidance”—informationregardingawardsinpriorcomparablecasesprovidedtothetrier
offactasguidancefordeterminingdamageawards—asamethodforimprovingthequality
ofawardsforpainandsufferingandpunitivedamages.Thepaperarguesthatsuch
methodsareimportantandpermissibleunderthelaw,anditappliesbasicstatistical
modelingandtechniquestoexplainhowandwhensuchmethodscanbeexpectedto
improvedamageawards.Thefourthpaper(coauthoredwithYangChen),Shrinkage
EstimationintheAdjudicationofCivilDamageClaims(forthcomingintheReviewofLaw&
Economics),6assumesthatthecomparable-caseguidancemethodsdiscussedabovecould
beappliedformulaically(or,equivalently,assumesthatthetrieroffactwouldincorporate
theinformationaccordingtoourmodel)andderivesarangeofstatisticalresultsregarding
theconditionsunderwhichsuchmethodswouldimprovethequalityofdamageawards.
Finally,thefifthpaper(coauthoredwithReaganRose),GuidingJurorswithPrior-
AwardInformation:ARandomizedExperiment,7reportsandinterpretstheresultsofa
factorialexperimentdesignedtotesttheconclusionsinthethirdandfourthpapers—and
specifically,totestthebehavioralassumptionsinthosepapersandwhethercomparable-
caseguidanceimprovesthequalityofawards(asdefinedinthepapersbelow)undera
robustrangeofconditions.8
Insummary,thepapersdemonstratethatthemethodsdiscussedarecapableof
improvingdamageawardssubstantially,andaregenerallypermissibleunderthelaw.
6HillelJ.Bavli&YangChen,ShrinkageEstimationintheAdjudicationofCivilDamageClaims,REV.OFL.&ECON.(forthcoming,2017).
7HillelJ.Bavli&ReaganRose,GuidingJurorswithPrior-AwardInformation:ARandomizedExperiment.
8Note,thepapershavebeenmodifiedfromtheiroriginalformforpurposesofconsistency.
4
I. AggregatingforAccuracy:ACloserLookatSamplingandAccuracyin
ClassActionLitigation*
1. Introduction
ProfessorCharlesAlanWrightremarkedthat“[u]nlesswecanusetheclassaction
anddevicesbuiltontheclassaction,ourjudicialsystemisnotgoingtobeabletocopewith
thechallengesofthemassrepetitivewrong.”1Indeed,UScourtsincreasinglygrapplewith
thelimitsofaggregationproceduresinmanagingtoday′slitigationneeds.Amongthemost
controversialofsuchproceduresistheuseofstatisticalsampling,andinparticular,
representative“bellwether”trials,toextrapolateaggregateproofofliabilityanddamages
foraclassofunlitigatedclaims.
In1990,withfederalasbestosfilingsaveraging1,140permonth—doubletherateat
whichsuchfilingswerebeingresolved—U.S.courtssearchedfornovellegalprocedures
* Thisarticleoriginallyappearedin14LAW,PROBABILITY&RISK67(2015).Citation:HillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation,14LAW,PROBABILITY&RISK67(2015).Itmayhavebeenmodifiedfromitsoriginalformforpurposesofconsistency.Indevelopingtheideaspresentedinthecurrentarticle,IbenefittedimmenselyfromtheadviceandguidanceofProfessorsDonaldRubinandAlanZaslavsky,andfromthethoughtfulcommentsofananonymousreviewer.Othermajorcontributors,towhomIoweparticulargratitude,includePengDing,RuobinGong,CarlMorris,JoeBlitzstein,KathrynSpier,DavidRosenberg,LouisKaplow,andthestudentsofDonaldRubin′sgraduateseminarcourseatHarvard.IowethankstotheDepartmentofStatisticsatHarvardUniversityforitssupportandtotheLaw,Probability&RiskEditorialBoardfortheirhelpfulcommentsandedits.
1Cimino, etal. v.Raymark Industries, Inc., etal., 751F. Supp.649,652 (E.D.Tex.1990) (citingH.Newberg,NewbergonClassActions17.06,at373(2ded.1985)).
5
capableofhandlingtheinfluxofclaimswhilemaintainingproceduraldueprocessand
ultimatelyajustresolutionoftheclaims.2Inthiscontext,controversystirredovertheuse
ofaggregationmechanisms,suchassampling,toresolvetheclaims.3
InCiminov.Raymark,4a1990asbestosclassaction,JudgeParkeroftheEastern
DistrictofTexasapprovedatrialplaninvolvingarandomsampleof160claimantsfroma
totalof2,298classmembers.Hedividedthepopulationofclassmembersintofivedisease
categoriesbasedontheclaimants′injuryclaims.Hethentookarandomsamplefromeach
categorytoformarepresentative160-claimantsamplegroup.Thedamagesclaimsofeach
randomlysampledclassmemberweresubmittedtoajury,andeachmemberofthesample
groupwasawardedhisindividualizedverdict.Then,theaverageverdictineachdisease
categorywascomputedandappliedtothenon-sampledmembersofeachcategory,
respectively.5TheFifthCircuitultimatelyrejectedthesamplingprocedure,rulingthatit
violatedthedefendant′sSeventhAmendmentrighttoindividualizeddeterminationsof
whethertheproductsatissuecausedplaintiffs′injuries,aswellasitsrighttohavejury
2MichaelJ.Saks&PeterDavidBlanck,JusticeImproved:TheUnrecognizedBenefitsofAggregationandSamplingintheTrialofMassTorts,44STAN.L.REV.815,815-19(1992).
3Anadhoccommittee,createdbytheChiefJusticeoftheU.S.SupremeCourttoexaminepotentialsolutionstothe enormous backlog caused by the asbestos litigation, found that the problem had “reached criticaldimensions,”andthatthecourtsareill-equippedtohandlethesituation.Id.at816(citingJudicialConferenceoftheUnitedStates,ReportoftheJudicialConferenceAdHocCommitteeonAsbestosLitigation,at2(1991)).Amongthemanyrecommendationsmade in itsreport, theCommitteeproposedthepossibilityofsamplingasbestosclaimsforlitigationandthenextrapolatingtheoutcomesoftheremainingclaimsfromthoseofthesampledclaims.
4751F.Supp.649(E.D.Tex.1990).
5Seeid.at652-54.
6
determinationsregardingthe“distinctandseparableissuesofactualdamagessufferedby
eachextrapolationplaintiff.”6
Thesentimentinthecourtsandintheliterature—thenandnow—isthattheuseof
samplingproceduresservespurposesofefficiency,butonlyatthecostoffairness,or
accuracy;andthatthe“benefitsofefficiencycanneverbepurchasedatthecostof
fairness.”7
Butina1992StanfordLawReviewarticle,ProfessorsMichaelSaksandPeter
Blancksoughttoaddresstheconstitutionalandreliabilityconcernsthatcourtsand
commentatorshavevoicedinopposingtheuseofsampling.Theydidnotsimplyarguethat
properlyimplementedaggregationcanprovidethesamelevelofreliabilityas
individualizedlitigation.Rather,theyclaimedthatinfact“aggregationaddsanimportant
layerofprocesswhich,whendonewell,canproducemorepreciseandreliable
outcomes”—that“theproceduralinnovationofaggregationprovidesaqualityofjustice
thatsurpasseswhatcourtshave,untilnow,beencapableofinanykindofcase.”8
6Cimino,etal.v.RaymarkIndustries,Inc.,etal.,151F.3d297(5thCir.1998).
7Malcolmv.NationalGypsumCo.,995F.2d346(2dCir.1993).SeeInreChevronU.S.A.,109F.3d1016,1023(5thCir.1997)(Jones,J.,concurring)(“asJudgeHigginbothamcautionedinInreFibreboardCorp.,thereisafinelinebetweenderivingresultsfromtrialsbasedonstatisticalsamplingandpurelegislation.Judgesmustbesensitivetostaywithinourproperboundsofadjudicatingindividualdisputes.WearenotauthorizedbytheConstitutionorstatutestolegislatesolutionstocasesinpursuitofefficiencyandexpeditiousness.”).InHilaov.EstateofMarcos,acontroversialdecisioninwhichtheNinthCircuitapprovedoftheuseofsamplingtoresolvethe damages claims of approximately 10,000 claimants, the court nevertheless emphasized that “[t]hestatisticalmethodusedbythedistrictcourtobviouslypresentsasomewhatgreaterriskoferrorincomparisontoanadversarialadjudicationofeachclaim.”103F.3d767,786(9thCir.1996).
8Saks&Blanck,supranote2,at815-16.
7
SinceCimino,theneedforeffectiveaggregationprocedureshasonlyintensified.But
assertionsbySaksandBlanck,aswellasotherauthors,thatsamplingcanincrease
accuracyaswellasefficiency,havebeenmetwithskepticismandageneralunwillingness
torelyonsuchassertionsinrulingonproposedaggregationprocedures.Instead,courts
havecontinuedtorejectsamplingonthegroundsthataccuracyshouldnotbesacrificedfor
thesakeofefficiency.Indeed,althoughcourtsandcommentatorshaveoftenrejected
samplingexplicitlyongroundsofprotectingthedefendant′sconstitutionalandprocedural
rights,9SaksandBlanckarelikelycorrectinremarkingthat“amajor—perhapsthemajor—
dueprocessconcerninanaggregatedtrialisthevalidityoftheoutcome.”10AsSaksand
Blanckemphasized,andcourtshavesuggested,“Themainargumentagainsttrialby
aggregationandsamplingassertsthatsuchtrialscannotgivethepartiesasaccuratea
resultastheywouldobtainthroughtraditionalbilateraltrials.”11
9See,e.g.,Wal-MartStores,Inc.v.Dukes,etal.,131S.Ct.2541,2561(2011)(rejectingsamplingongroundsthattheRulesEnablingActprohibits interpretingRule23 so as to “abridge, enlargeormodify any substantiveright.”);Ortizv.FibreboardCorp.,527U.S.815,845(1999)(citingAmchemProducts,Inc.v.Windsor,521U.S.591,613(1997)).
10Saks&Blanck, supranote2, at 833. Saks andBlanck explain the instrumentalist argument that theDueProcessClauseexists toservepurposesofaccuracy—that “[t]herights tonotice,hearing,andcounseleachcontributetothegoalofaccuracy.”Id.(citingJointAnti-FascistRefugeeComm.v.McGrath,341U.S.123,172(1951)(Frankfurter,J.,concurring));MartinH.Redish&LawrenceC.Marshall,AdjudicatoryIndependenceandtheValuesofProceduralDueProcess,95YALEL.J.455,476-77(1986).TheycommentthattheSupremeCourt′sbalancingapproachinMathewsv.Eldridge,424U.S.319,334-35(1976),“attemptstoensuretheaccuracyofoutcomefromtheprocess.Itisrelativelylessfocusedonthefairnessorperceivedfairnessoftheproceduresthemselves.” Saks&Blanck, supranote2, at 827 (citing JerryL.Mashaw,The SupremeCourt′sDueProcessCalculusforAdministrativeAdjudicationinMathewsv.Eldridge:ThreeFactorsinSearchofaTheoryofValue,44U.OFCHICAGOL.REV.28(1976)).
11Saks&Blanck,supranote2,at833.SeealsoInreChevronU.S.A,Inc.,109F.3dat1020(“ourproceduraldueprocessconcernsfocusonthefactthattheprocedureembodiedinthedistrictcourt′strialplanisdevoidofsafeguardsdesignedtoensurethattheclaimsagainstChevronofthenon-representedplaintiffsastheyrelatetoliabilityorcausationaredeterminedinaproceedingthatisreasonablycalculatedtoreflecttheresultsthatwouldbeobtainedifthoseclaimswereactuallytried.”).
8
Arguably,theprimarysourceofsuchskepticism,andtheunwillingnessofcourts
andcommentatorstorelyonassertionsthatsamplingcanincreaseaccuracyaswellas
efficiency,isthegeneralitywithwhichsuchassertionshavebeenmade.Inparticular,such
assertionshavenotbeendevelopedformally,andtheliteraturehasnotexaminedtheeffect
ofsamplingonaccuracy,inanyrigorousform,underconditionsapplicabletoreal-world
classactions.Indeed,inmostcircumstances,samplingdoesnotincreaseordecrease
accuracycategorically;rather,asexplainedbelow,itscapacitytoincreaseaccuracyisa
functionoftheparametersassociatedwithaparticularclassofclaims.Therefore,adeeper
understandingoftheconditionsunderwhichsamplingwillincreaseaccuracyisnecessary.
Inthecurrentarticle,Iintroduceaframeworkforexaminingtheconditionsunder
whichsamplinginthecontextofclassactionlitigationcanincreaseaccuracyinthelaw.In
particular,Idevelopamodelforstudyingtheeffectsofsamplingonaccuracyandfor
derivingtheoptimalsamplesize,givenasetofparametersassociatedwithaclassof
claims.Ithenintroducemethodsforestimatingclassparametersandforincreasingthe
utilityofclaimaggregation.
IbegininSection2bymotivatingtheproblemwithabriefoverviewofsamplingin
thecontextofclassactionlitigation,andadiscussionregardingtheimportanceof
understandingtheconditionsunderwhichsamplingcanincreaseaccuracy.InSection3,I
discussinfurtherdetailthemeaningofaccuracyandalsotheaspectofthelawthat
underliestheaccuracy-enhancingbenefitsofsampling:judgmentvariability.InSection4,I
introduceabasicframeworkforexaminingtheeffectsofsamplingonaccuracy,andfor
9
derivingtheoptimalsamplesize,givenclassparametersandspecifiedconstraints.In
Section5,Idiscussanumberofimportantextensions,includingpossibilitiesforparameter
estimationandtheuseofsequentialsampling,stratificationtechniquesthatmayallowfor
thereductionofclaimheterogeneityandtherebyincreasetheutilityofclaimaggregation,
andissuesrelatedtoincentivestoinitiateclaimsandtosettleundercircumstancesofclaim
aggregation.InSection6,Iconclude.
2. AggregateProofandSamplinginClassActionLitigation
Aclassactionisalegalprocedurebywhichmultiple(oftenmany)legalclaimsare
aggregatedintoasinglecaseforjointdetermination.Classactionsconstituteavery
substantialproportionofclaimsintheUSA.Efficiencyistheprimarypurposeoftheclass
actionprocedure,withoutwhichcourtswouldbeoverwhelmedwithclaimsbroughtfor
individualizedlitigation(leadingtoextremedelays,etc.),andmanyclaimantswith
legitimateclaimswouldbeunabletoaffordbringingtheirclaimsindividuallyinthefirst
instance.
Beforeacourtwillapprove,or“certify,”aproposedclassforthisformoflitigation,
theclassrepresentativesmustprovetothecourtthattheclaimsinvolvecommon
questionsoffactorlaw,andthatitmakessensetotrytheclaimstogetherasaclassaction
ratherthanindividually.Therepresentativesmustshowthattheclaimsaresufficiently
numeroustojustifytheclassactionprocedure;thattheclaimsintheproposedclassare
sufficientlycommon;thattherepresentativeclaimsaretypicaloftheremainingclaims;and
thattherepresentativescanadequatelylitigatetheseclaimsonbehalfoftheclass.In
10
addition,theproposedclassmustsatisfyoneofthreeotherrequirements—frequently,that
commonissuespredominateoverindividualissues.
Itisanarduousprocesstoachieveclasscertification.Inasense,itisatrialinitself
todeterminewhetheraproposedclassshouldbecertified.Afterall,iftheclassisnot
certified,mostclaimantsareunlikelytobringtheirclaimsindividually;andiftheclassis
certified,theclassactionhasthepotentialtobankruptevenlargecompanies,andthe
claimantswillhaveenormouspoweroverthedefendant(s)inelicitingafavorable
settlement.
Anaspectofclasscertificationthathasprovenparticularlydifficultforplaintiffsis
therequirementthataplaintiffclassproveliabilityanddamagesonaclasswidebasis.As
theSupremeCourtheldinWal-Martv.Dukes,whatisimportantindeterminingwhetherto
certifyaclassisnotsimplytheraisingofcommonquestions,butthecapacityoftheclass
proceedingtoproducecommonanswerscentraltothelitigation.Importantly,anindividual
plaintiffmaynotescapetherequirementsofprovingliabilityorinjurymerelybyjoininga
class.Plaintiffsmustbeabletoshowthatthedefendantisliablewithrespecttoeach
claimant,andthatthedefendant′sconductcausedinjurywithrespecttoeachclaimant.
Itishere,inthecontextofprovingclasswideliabilityanddamages,thatclass
plaintiffshaveattemptedtoemploysamplingproceduresandbellwethertrials.12
12“Bellwethertrials,”or“testcases,”havebeenusedinvariouslegalcontexts—suchasantitrustandmass-tortlitigation—andforarangeofpurposes.Asdiscussedfurtherbelow,however,courtshavebeenreluctanttoapprove suchprocedures for purposes of determining liability anddamages. Arguably, prior to a string ofnegative court rulings in andafter2011, therewas risingmomentum for theuseof, or at least for furtherexploration of, such procedures in the mass-tort context. See generally Laura E. Ellsworth & Charles H.Moellenberg, Jr.,Bellwether Trials, 2 Business and Commercial Litigation in Federal Courts §14:47, 3d ed.(2013);Manual forComplexLitigation§22.315,TestCases,Federal JudicialCenter,4thed.(2004);EldonE.
11
Sampling-basedclaimaggregationhastakentwogeneralforms.Thefirstform
involvesaggregatingandsamplingevidencepriortotrial—e.g.,evidencethatthe
defendant′sbehaviorcausedtheharmallegedbytheplaintiffs—followedbythe
presentationofthesampledevidencetoajury,whichwillthendetermineanoutcomefor
theentireclass.13Forexample,inHilaov.EstateofMarcos,aclassactionseekingdamages
forhumanrightsabuses,thedistrictcourtusedarandomsampleof137claims,divided
intocategories(torture,summaryexecutionanddisappearance),fromatotalof
approximately10,000claims,todetermineappropriatecompensatorydamages.14The
districtcourtappointedaspecialmastertosupervisethedepositionsinthePhilippinesof
the137sampledclaimantsandtheirwitnesses.Thespecialmasterthenreviewedtheclaim
formsandthedepositions,evaluatedthetestimonybasedoninstructionsprovidedbythe
districtcourt,andmaderecommendationsregardingthevalidityoftheclaims.He
recommendedthat6ofthe137claimsinthesamplebefoundnotvalid;and,forthe
Fallonetal.,BellwetherTrials inMultidistrictLitigation,82TULANEL.REV.2323(2008);AlexandraD.Lahav,BellwetherTrials,76GEORGEWASH.L.REV.576(2008);JohnC.Coffee,Jr.,ClassWars:TheDilemmaofTheMassTortClassAction,95COLUM.L.REV.1343(1995);DeborahR.Hensler&MarkA.Peterson,UnderstandingMassPersonalInjuryLitigation:ASocio-LegalAnalysis,59BROOKLYNL.REV.961(1993).
13SeegenerallyLaurensWalker&JohnMonahan,SamplingLiability,85VIRGINIAL.REV.329(1999).Notethattheuseofsamplingandstatisticalanalysisinthegeneralevidentiarycontexthasalongandwell-establishedhistory inU.S. courts.See generally DanaG.Deaton,TheDaubert Challenge to the Admissibility of ScientificEvidence, 60 AM. JURISPRUDENCE TRIALS 1 (2014); Crashworthiness Litigation, 2d (AAJ Press) §22, ExpertTestimony:TheEffectoftheDaubertProgeny(2013);R.ClaySprowls,TheAdmissibilityofSampleDataintoaCourtofLaw:ACaseHistory, 4UCLAL.REV.222 (1956-1957);ShariSeidmanDiamond,ReferenceGuideonSurveyResearchinReferenceManualonScientificEvidence359-423,3ded.,FederalJudicialCenter/NationalAcademy of Sciences (2011) (citing cases and literature); Joseph L. Gastwirth, Reference Guide on SurveyResearch,36JURIMETRICSJ.181(1996)(reviewingDiamond′sReferenceGuideonSurveyResearchinReferenceManualonScientificEvidence(1994),anddiscussingrelevantcasesinthetrademark-infringementcontext).
14103F.3d767,782-84(9thCir.1996).
12
remaining131validclaimsinthesample,hemadedamagesrecommendationsforeachof
thethreecategories.Finally,hemaderecommendationsondamageawardsforthe
remaining(non-sampled)classmembersbasedonhisrecommendationsforthesampled
claims.Inparticular,basedonhisfindingthat6ofthe137claims(4.37%)wereinvalid,he
recommendeda5%“invalidityrate”fortheremainingclaims,andherecommendedan
awardfortheclassdeterminedbymultiplyingthenumberofclaimsineachsubclass,after
discountingbytheinvalidityrate,bytheaverageawardrecommendedfortherandomly
sampledclaimsineachsubclass,respectively.Ajurytrialoncompensatorydamageswas
thenheld.Anexperttestifiedregardingthevalidityofthesamplingmethodologyandthe
useofinferentialstatistics,andtestimonyfromthe137sampledclaimantsandtheir
witnesseswasintroduced.Then,thespecialmastertestifiedregardinghis
recommendations,andhisreportwasprovidedtothejury.Thecourtinstructedthejury
thatitcouldaccept,modifyorrejecttherecommendations,andthatitcanreachitsown
judgmentastodamagesonthebasisoftheevidenceofthesampledclaimants.After
deliberatingfor5days,thejuryfoundagainstonly2ofthe137claimantsinthesample,but
generally(withsomeexceptions)adoptedthespecialmaster′srecommendations.The
districtcourtthenenteredjudgmentfor135ofthe137claimantsintheamountsthejury
awarded,andenteredjudgmentfortheremainingclaimantsineachofthethreesubclasses
intheamountsthejuryawarded,tobedividedprorata.15
15Id.;seealsoBlueCrossandBlueShieldofNewJersey,Inc.v.PhilipMorris,Inc.,178F.Supp.2d198(E.D.N.Y.2001)(Individualactionbyhealthinsureragainsttobaccocompaniesinwhichasampleof156deponentswasselected,andstatisticalevidencewaspresentedtothejuryincombinationwithstudies,relevantportionsofvideotapeddepositiontestimony,andexperttestimonytoenablevalidstatisticalinferencetoprovecausation-todeterminewhethersmokerswereinfactdeceivedbystatementsmadebythetobaccoindustry);Walker&
13
Thesecondform—thefocusofthecurrentarticle—involvestheuseof
representative“bellwethertrials”toresolveclasswideissues.Theprocedureapprovedby
JudgeParkerinCiminov.Raymarkisillustrative.InCimino,aclassofasbestosclaimswas
dividedintofivediseasecategories,andasmallrandomsampleofclaimswasselectedfrom
eachcategoryforindividualizedjurydetermination.16Thecourtawardedthesample-
groupclaimantstheirrespectiveindividualizeddeterminations,andthentheaverage
awardineachdiseasecategorywascomputedandawardedtotheremaining(non-
sampled)claimantsineachcategory,respectively.17
ConsidertheimportantcaseWal-Martv.Dukes,18aclassactionlawsuitby
approximately1.5millioncurrentandformerfemaleemployeesagainstWal-Martalleging
thatthesuperchainstorediscriminatedagainstthemonthebasisofgender.Theplaintiffs
arguedthat,inordertoshowclasswideliability,theymustshowthatWal-Martindeed
discriminatedagainstwomen,andthatthe1.5millionclassmemberswerefemaleswho
wereemployedbyWal-Martduringtherelevantperiod.Theyarguedthatthisissue-
Monahan,supranote13(discussingsampling in thetobacco litigationandEstateofMarcos,anddescribingcases leading up to Estate of Marcos). See generally In re Fibreboard Corp., 893 F.2d 706 (5th Cir. 1990)(rejectingthe“lumpsum”approach,inwhichevidencefromselectedtypicalplaintiffsprovidethebasisofthejury′sdeterminationofadamagesawardfortheentireclass).
16Methods for selecting bellwether trials can be categorized as follows: “(i) plaintiffs′ counsel selects thesample;(ii)eachsideselectsanequalnumberofsamplecases;(iii)thecourtselectsthesamplefromnomineesproposedbytheparties;or(iv)thesamplesarerandomlyselectedfromagreed-oncategoriesofclaimants.”2McLaughlinonClassActions8:6(10thed.).SeeSterlingv.VelsicolChemicalCorp.,855F.2d1188,1196n.6(6thCir.1988).Hereafter,unlessstatedotherwise,thereadershouldassumethatclaimsareselectedforthesamplegrouprandomlyfromtheclass,orfromclassstrataiftheclassisstratified,suchasinCimino.
17SeegenerallyCimino,751F.Supp.at652-54.Note,althoughCiminoinvolvedsamplingasameansofresolvingdamagesissues,hereinIconsidersamplinginabroadercontext—includingitsusetoresolveissuesofliability.
18131S.Ct.2541,180L.Ed.2d374(2011).
14
whetherWal-Martdiscriminatedagainstwomen-isthecommonquestionthatbindsall
membersoftheclass,andthatmakesaclassaction,ratherthanindividualizedlitigation,
appropriate.
Thedefensecounteredthat,asamatteroflaw,ifanemployerissuedongroundsof
discriminationthenirrespectiveofwhethertheemployerwasdiscriminatoryornot,the
employermayputforththedefensethattheparticularconductallegedbyagivenplaintiff
wascausedbylegitimate,ratherthandiscriminatory,purposes(e.g.,thataparticular
employeestolefromthecashregisterandwasfiredonthosegroundsalone).Itarguedthat
thisaffirmativedefensemustapplyonanindividualizedbasis,ratherthanthroughsome
shortcutthatmaybeappliedcommonlytotheclassasawhole.
Thelowercourtsapprovedatrialplanthatwasintendedtoovercometheproblem
describedbythedefendants.Theplaninvolvedtakingasmallsampleofclaims(the
“samplegroup”)thatwouldbeexaminedtodeterminewhatproportionofthesample
wouldresultinadeterminationofWal-Mart′sliability.Further,damageswouldbe
determinedforeachofthesampledclaims.Theclaimsinthesamplegroupwouldreceive
individualizeddeterminations.Butthecourtwouldthenassigndamagestotheremainder
oftheclass(the“extrapolationgroup”)byaveragingthedamagedeterminationsfromthe
samplegroup(includingzerodamagesforclaimsinwhichWal-Martwasfoundnotliable)
andmultiplyingthataveragebythenumberofremainingclaims.
TheSupremeCourtreversedthedecisionofthelowercourtsandoutrightrejected
theuseofsamplingtoproveclasswideliabilityanddamageswheresuchsamplingabridges
15
therightofadefendanttodefenditselfonanindividualizedbasisunderthesubstantive
law.TheSupremeCourtviewedthetrialplanasaformof“TrialbyFormula”and
“disapprove[dof]thatnovelproject.”
Wal-Martreaffirmedandperpetuatedasignificantbodyofcaselawrejectingthe
useofsamplingasameansofofferingaggregateproofofclasswideliabilityanddamages.19
InthewakeofWal-Mart,anunderstandingofconditionsunderwhichsamplingcan
increaseaccuracyaswellasefficiencyisoffundamentalimportance.ProfessorWrightwas
likelycorrectwhenhewarnedofthenecessityofbuildingontheclassactionprocedureto
addressthechallengesofthemassrepetitivewrong.20Arguably,inlightofthenatureof
today′ssocialandeconomicinteraction,theneedforsuchprocedureshasneverbeen
greater.Thecourtsareneverthelessincreasinglyunwillingtobenefitfromtheefficiencies
ofaggregation,butunderthefalsepremisethatsuchbenefitscomeonlyatthecostof
accuracy.Butperhapsthegreatestbenefitsofaggregationinfactlieinitsabilitytoincrease
accuracyinadditiontoefficiency.
AsSaksandBlancksuggested,thevalidityofthecase′soutcomeisamajor(ifnotthe
major)sourceofcourts′antagonismtowardssampling,includingantagonismexpressedin
19See,e.g.,McLaughlinv.AmericanTobaccoCo.,522F.3d215,224(2dCir.2008);Cimino,151F.3dat297;InreFibreboardCorp.,893F.2dat706;Bascov.Wal-MartStores,Inc.,216F.Supp.2d592(E.D.La.2002).SeealsoEspenscheidv.DirectSatUSA,LLC,705F.3d770(7thCir.2013)(holdingthatplaintiffs′proposedtrialplanwasnot feasibleduetovarianceindamagesacrossclassmembers, thusrejectingplaintiffs′proposaltoaddresssuchvariancebypresentingtestimonyattrialfrom42representativemembersoftheclass).ButseeSaks&Blanck,supranote2,at837(emphasizingthat“fromtheviewpointofdefendants,eveniftherearerelativelylargeerrors,withnumerousover-andunder-awards,allofthosedifferenceswillcanceleachotheroutandtheaverage award will be the same in the collective trial as it would have been with the individualizeddeterminations").Forcaselawanddiscussion,see2McLaughlinonClassActions,supranote16,§8:7.
20Seesupranote1.
16
termsofcourts′concernfortheeffectofsamplingonadefendant′sproceduralrights.21If
thisisthecase,thenanunderstandingoftheconditionsunderwhichsamplingcanincrease
accuracymayleadcourtstoreversetheircurrentcourse.22
Further,regardlesswhetheraccuracyisatthecenterofjudicialdecisionsrejecting
sampling,anunderstandingoftheaccuracy-enhancingbenefitsofsamplingenablescourts
andlawmakerstobetteraccountforthecostsofsubstantivelawsthatprevent,orthatdo
notenable,suchprocedures.Infact,currently,numerousfederalstatutesexplicitlyor
impliedlypermitsamplingasatoolforprovingdamages.Forexample,theHart-Scott-
RodinoAntitrustImprovementsActstatesthatinparenspatriaeactionsbystateattorneys
generalinwhichtherehasbeenadeterminationthatadefendantagreedtofixprices,
“damagesmaybeprovedandassessedintheaggregatebystatisticalsamplingmethods,by
thecomputationofillegalovercharges,orbysuchotherreasonablesystemofestimating
21SeeSaks&Blanck,supranote2,at833;seealsosupranotes10-11,andaccompanyingtext;2McLaughlinonClassActions,supranote16,§8:7.Note,arguablyWal-Martmaybeviewedasaspecialcase—andarguablydistinguishable from other cases in which a plaintiff class seeks to employ sampling to prove liability ordamages—inthatitwasinWal-Mart′sinteresttodefendagainsttheplaintiffs′claimsonaclaim-by-claimbasis,independentofthevalidityofthedamagesincurredbyWal-Martintheaggregate.Inparticular,itwasinWal-Mart′sinteresttosortvalidclaimsfrominvalidclaimsandtherebysetastrongprecedentforemployeesthattheywillberewardedbasedontheirperformance,andnotbasedonwindfalllegaldamages.Arguably,acourtmayfulfillthissortingfunctionaswellbyorderingpost-awardallocationhearings.
22Note,SaksandBlanckdoaddresstheimportanceofmaintainingproceduraljusticeforitsownsake,buttheyconsidertheproceduralinjusticethatcanresultfromtraditionalproceduresforthemajorityoftheclass,andthey ultimately conclude that, at least with respect to the plaintiffs in actions like the asbestos litigation,aggregationcanprovidemoreproceduraljusticethanthealternatives.SeeSaks&Blanck,supranote2,at838-39.SaksandBlanckarguethat“acloserlookattheaggregatedtrial,atleastinthemasstortcontext,suggeststhat this procedure does not necessarily violate traditional notions of due process under the Fifth andFourteenthAmendments.”Theyassertthat,“[i]nfact,theabsenceofsuchproceduresistantamounttodenyingmany litigants theirdueprocess trial rightsaltogether.” Id. at826.Further, regardlesswhetherproceduraljusticeisvaluedinitsownright,fewwouldarguethatsuchvaluecanbeviewedentirelyindependentlyofitsinstrumentalvalueinensuringaccurateoutcomes,orthat“proceduraljustice”shouldbepreservedregardlessofthepotentialcostswithrespecttoaccuracy.
17
aggregatedamagesasthecourtinitsdiscretionmaypermitwithoutthenecessityof
separatelyprovingtheindividualclaimof,oramountofdamageto,personsonwhose
behalfthesuitwasbrought.”23
Thus,inthefollowingsections,Idevelopaframeworkforexaminingtheconditions
underwhichsamplingcanincreasetheaccuracyoflegaldeterminations.Ibeginby
describingtheconceptsofaccuracyandvariabilityinthelaw.
3. AccuracyandVariabilityintheLaw
Centraltothedebateoversamplingandtotheframeworkdevelopedhereinarethe
conceptsofaccuracyandjudgmentvariability.Ibegin,inthecurrentsection,withageneral
discussionoftheconcepts,andthenintroduceamoreformalconceptualizationinSection4
below.
3.1 TheMeaningofAccuracy
Onerelativelysimpleapproachtodescribingaccuracyinthelawistoassumethat,
foreverylegalclaim,thereexistsa“correct”outcomethatcan,intheory,bedeterminedas
afunctionofthecompletefactssurroundingagivenclaimandthe“true”stateofthelawat
thetimeoftheclaim.24Inthissense,assumingthatcompleteknowledgeofthefactsandthe
2315U.S.C.A.§15d;seealsotheTruthinLendingAct,15U.S.C.A.§1640(a);theEqualCreditOpportunityAct,15U.S.C.A.§§1691etseq.SeegenerallyWalker&Monahan,supranote13.Foradescriptionoftheroleofstatisticsinproving individualcausationanddamages,see2McLaughlinonClassActions,supranote16,§8:7.Note,undercertaincircumstances,anunderstandingoftheconditionsunderwhichsamplingcanincreaseaccuracymayencouragelitigantsthemselvestoagreetotheuseofsampling.
24Amorecomplexapproachistoconsideraprobabilitydistributionof“correct”outcomesassociatedwitheachandeverylegalclaim.
18
stateofthelawisunavailable,atrialwillresultinanestimateofthecorrectoutcome.25As
such,eachlegaloutcomeinvolvesanerrortermthat,ifpossibletocompute,would
describethedistancebetweentheactualoutcomeandthecorrectoutcome.Wecanthen
defineaccuracyastheproximityoftheactualverdicttothecorrectverdict.26
ThisdescriptionisconsistentwithSaksandBlanck′sassertionthatitmakessense
“tothinkofthe‘true’awardastheaverageofthepopulationofpossibleawards”that
wouldresultfromtryingthesamecaserepeatedlyforaninfinitenumberoftimesunder
variousconditions(e.g.,beforedifferentjuries,bydifferentattorneys,usingdifferent
permutationsoffacts,etc.).27Forsimplicity,Iignorethepotentialforbiasandadoptthis
formulationofthe“correct”outcomeassociatedwithagivenclaim.28
Suppose,forexample,thatacigarettesmokerfilesalawsuitagainstamajor
cigarettemanufacturerforfailuretoadequatelyinformtheconsumeroftheharms
associatedwithsmoking.Followingtrial,ajuryreturnsaverdictfindingthecigarette
manufacturerliableandawardstheplaintiffdamagesintheamountof$800,000.Wecan
25Findinganappropriateoutcomecanbeunderstood, instatistical terms,asa “missing-data”problem.SeegenerallyDonaldB.Rubin&RoderickJ.A.Little,StatisticalAnalysiswithMissingData,Wiley,NewYork(2ded.2002).
26SeegenerallyJonathanJ.Koehler&DanielShaviro,VeridicalVerdicts:IncreasingVerdictAccuracyThroughtheUseofOvertlyProbabilisticEvidenceandMethods,75CORNELLL.REV.247(1990)(discussingthemeaningof“accuracy”inthelaw).
27Saks&Blanck,supranote2,at833-34.
28Butseeinfranote41.Note,ifjudgmentvariabilitywereentirelyduetovariabilityinthecompositionofthejury,we couldarrive at an intuitivevariantof SaksandBlanck′s “true” awardby imaginingahypotheticalsituation inwhicheverypossible jury inagivengeographicregionobservesthetrialand independently(ifhypotheticallypossible)determinesaverdict.Thenthe“correct”outcomemaybedescribedastheaverageofallsuchverdicts.
19
assumethat,givencompleteinformationregardingthelawandthefactsofthecase,wecan
computethecorrectoutcome;butsinceperfectinformationregardingthefactsandthelaw
isunavailable,thejuryarrivesataverdict,whichservesasanestimateofthecorrect
outcome.Inourexample,theaccuracyoftheverdictisdefinedastheproximityofthe
verdict,$800,000,tothecorrectoutcome.29
Thus,asdiscussedabove,accuracyisoftenunderstoodasafundamentalobjective
ofthelaw.SaksandBlanckdiscussthisinterestwithinthecontextofwhattheyrefertoas
“distributivejustice”;andtheyhighlighttheinstrumentalistperspectivethat“the
constitutionalpurposeofthedueprocessclauseistoensurethemostaccuratedecision
possible.”30Further,however,maximizingtheaccuracyoflegaldeterminationsislikelyto
servetheaimsofthelaw,whetherornotaccuracy,ordistributivejustice,isitselfthe
primaryobjectiveofthelaw.31Whetheraccuracyisunderstoodasameansofachieving
29 Itmay bemore intuitive to consider the concept of a “correct” verdict in the context of a criminal trial.Consider,forexample,theO.J.Simpsonmurdertrial.Pollsshowthatover50%ofAmericansbelievethatthejuryarrivedatanincorrectverdict.Implicitinthepublic′sdisagreementwiththeverdictisanassumptionthatthereexistsa“correct”outcome.Theframeworkdescribedaboveisintuitive:hadthejuryknownthetruefactsofthecase,andhadtherebeennoambiguityregardingtheapplicationofthelawtothefactsofthecase,thejurywouldhavearrivedatthecorrectconclusion.Butgivenambiguityregardingeitherthefactsofacaseorthe state of the law, it is unclearwhether a criminal defendant in fact satisfied the elements of the crimecharged;andthe jurymustarriveataverdict—“guilty”or“notguilty”—whichservesasanestimateof thecorrect outcome, “guilty” or “not guilty.” Further, given a finding of guilt, the court must determine anappropriate punishment (e.g., an appropriate prison sentence), which can similarly be understood as anestimateofsomecorrectoutcome.Thus,ultimatelythecourtmayarriveataprisonsentencethatservesasanestimateofsomecorrectsentence,whereafindingof“notguilty”translates,forexample,toaprisontermofzero.
30Saks&Blanck,supranote2,at833(citingRedish&Marshall,supranote10,at476-77).
31Ithasbeenargued,forexample,thatthelawshouldaimtomaximizewelfareratherthanfairness.SeeLouisKaplow & Steven Shavell, Fairness Versus Welfare, 114 HARV. L. REV. 961 (2001). Regardless whethermaximizingaccuracyisdeemedtobeafundamentalgoalofthelawinandofitself,thereisastrongargumentthataccuracy(oratleasttheperceptionthereof)isfundamentaltoachievingalternativegoals,suchaswelfare.Forexample,alowdegreeofaccuracyinthelawmayservetodilutethedeterrenceeffectintendedbythelaw;
20
importantlegalobjectives,oritselfacriticalobjectiveoflegalprocedure,theroleof
accuracyinthelawisfundamental.Further,asemphasizedabove,concernforaccuracyis
atleastanimportantfactor—ifnottheprimaryfactor—underlyingthewidespread
rejectionofsampling-basedaggregationinthecontextofclassactionlitigation.
Therefore,throughoutthearticle,Iassumethat,withrespecttosampling,accuracy
isafundamentalobjectiveoflegalprocedure.Further,Iassumethatsampling,ingeneral,
promotesgoalsofefficiency,sincesampling-basedtrialplansarecommonlyofferedasan
alternativetoindividualizedlitigation.However,Ireturntothematterofefficiencyin
Section5.
3.2 Judgmentvariability:ASourceofErrorintheLaw
Theclassactionprocedureallowsacourtsimultaneouslytodecide,withbinding
effect,numerousclaimsinvolvingcommonissues.Atthecostofforegoingindividualized
litigation,theclassactiondeviceoffersarangeofbenefits—primarily,litigationefficiency
andeconomy,andtheprotectionofrightsofindividualswhomaynotbeabletobring
claimsonanindividualbasis.32
andconversely,ahighdegreeofaccuracyinthelawmayservetoenhancesucheffects.Tobesafe,accuracy—evenifnottheprimarygoaloflaw—canbesaidtofacilitatethelaw′sobjectives,suchaswelfare.
32Am.Pipe&Const.Co.v.Utah,414U.S.538,553(1974);Crown,Cork&SealCo.,Inc.v.Parker,462U.S.345,349(1983)(statingthattheprincipalpurposesoftheclassactionprocedurearethe“promotionofefficiencyandeconomyoflitigation”);Andrewsv.ChevyChaseBank,545F.3d570,577(7thCir.2008)(emphasizingthattheprimarypurposesof theclassactionare judicialeconomyandefficiency);Haleyv.Medtronic, Inc.,169F.R.D.643,647(C.D.Cal.1996)(“Classactionshavetwoprimarypurposes:(1)toaccomplishjudicialeconomybyavoidingmultiplesuits;and(2)toprotecttherightsofpersonswhomightnotbeabletopresentclaimsonanindividualbasis.”);InreCaesarsPalaceSec.Litig.,360F.Supp.366,398(S.D.N.Y.1973)(suggestingthattheprimarypurposeof theclassactiondevice is“togivesmall investorsareasonableopportunitytovindicatetheirclaimsinamannerwhichwillnotplaceanunduefinancialburdenuponthem”).
21
Samplinghasbeenusedasameansofpreservingtheclassactionevenwhere
plaintiffsareunabletootherwiseofferclasswideproofofliabilityanddamages.Theideais
todetermineoutcomesthroughindividualizedlitigationforasmallsampleofclaims,and
thentoestimateoutcomesfortheextrapolation-groupclaimsintheformofanaggregate
determinationextrapolatedfromthesample-groupdeterminations.Opponentsof
aggregateproofarguethatwhereclasswideliabilityanddamagescannotbeshownabsent
extrapolationfromasamplegroup,thecourtshouldrejecttheclassaction,e.g.,infavorof
individualizedlitigation,whereineachplaintiffmustbringherclaimindividuallyifatall.
Thatis,opponentsofsamplingarguethatthecourtshouldnotallow“proceduraleconomy
toovershadowsubstantivelaw,”33itshouldnotsacrificeaccuracyforthesakeof
efficiency.34
Butopponentsofsamplinghaveneglectedacriticalfeatureoflitigation:as
highlightedabove,allverdictsare,inasense,estimatesofthetruth;andtryingonecase
beforetwoindependentjuriesishighlylikelytoresultintwodifferentestimatesofthe
correctoutcome.
Intermsofvariability,opponentsofsamplinghavefocusedontheerrorthatresults
fromextrapolation—e.g.,fromapplyingtheaverageofthesample-groupdeterminationsto
33SabyGhoshray,HijackedbyStatistics,RescuedbyWal-Martv.Dukes:ProbingCommonalityandDueProcessConcernsinModernClassActionLitigation,44LoyolaU.ChicagoL.J.467,470(2012).SeegenerallyMalcolm,995F.2dat346.
34Seesupra§2.Foradiscussionofconstitutionalargumentsagainstsampling,seegenerally JosephBarton,Utilizing Statistics and Bellwether Trials in Mass Torts:What Do the Constitution and Federal Rules of CivilProcedurePermit?8WILLIAMANDMARYBILLOFRIGHTSJ.199(1999).
22
theremainingclaims.Assumingthesamplegroupisrepresentativeoftheclassasawhole,
extrapolationerrorisafunctionofclaimvariability.Ifallclaimswerehomogeneous,
deservingequalawardsofdamages,thenapplyingtheaveragedeterminationinthesample
groupoverallclaimsintheextrapolationgroupwouldcauseminimalerror.Ontheother
hand,iftheclassentailsahighdegreeofclaimvariability,thenapplyingasinglepoint
estimate—suchastheaveragedeterminationinthesamplegroup—toallclaimsinthe
extrapolationgroupwillresultinahighdegreeoferror.Thisisalegitimateconcern;and
individualizedlitigationisaneffectivemeansofaddressingsucherror.Thatis,regardless
thedegreeofclaimvariability,ifclaimsaredecidedindividually,thereisnoextrapolation,
andthereforenoextrapolationerror.
However,opponentsofsamplinghaveneglectedadifferentformofvariability:even
iftheclaimsinaclassare(i)entirelyhomogeneous,and(ii)litigatedindividually,there
wouldneverthelessbesignificantvariabilityintheverdictsdeterminedforthoseclaims.35I
refertothisformofvariabilityasjudgmentvariability.Judgmentvariabilityresultsfroma
rangeofsources,includingjurycomposition,variabilityinthepresentationofevidence,
variabilityinthejudgeassignedtopresideoverthecase,etc.
Judgmentvariabilitycanbeunderstoodasaverysignificantsourceoferrorinthe
law.Forexample,imagineaclassof1millionhomogeneousclaimsbroughtinthecontext
ofaclassactionlawsuit(against,forexample,thelargestcigarettemanufacturers).Ajury
35See Saks&Blanck, supranote2;EdwardK. Cheng,When10Trials areBetterThan1000:AnEvidentiaryPerspectiveonTrialSampling,160U.OFPENN.L.REV.955,958-60(2012).
23
verdictintherepresentativeactionthatismerely$1,000greaterorsmallerthanthe
correctverdict—adifferentialcausedbyjudgmentvariability—wouldresultinawhopping
totalerrorvalueof1,000,000∗$1,000=$1billion.
Courtsareinfactwillingtoacceptadegreeoferrorinordertoavoidtheburdens
associatedwithlitigating1millionclaimsindividually.Buttheerrorthatcourtshave
acknowledgedandacceptedinreturnforsuchproceduralefficiencyisthatassociatedwith
variabilityinclaims,ratherthanthatassociatedwithjudgmentvariability.36Indeed,even
litigatingeachofthemillionclaimsindividuallywouldresultinaverylargeerrorvalue,as
eachofthemillionclaimsinvolvesanerrortermresultingfromjudgmentvariability—and
sothetotalerrorstillinvolvestheaggregationof1millionerrorterms.
Butimaginenowa(costly)hypotheticalprocedureinwhicheachandeveryclaim
werelitigated10timesindependently,andinwhichtheoutcomeassociatedwitheach
claimwerecomputedbytakingtheaverageofthe10verdictsassociatedwiththatclaim.
Thatis,startbytakingthefirstclaimandlitigateitbeforetenindependentjuries37to
obtain10independentverdicts.38Then,assigntheaverageofthe10verdictsasthe
36Ofcourse,iftheclaimsaretooheterogeneous,thecourtwillrefusetocertifytheclass.Theclasscertificationproceduredescribedabove is intendedtoensuretherepresentativenessof the litigatedclaims—inessencesomesignificantdegreeofhomogeneity.Tobeclear,ourcurrentexampleinvolveshomogeneousclaimsandthereforezeroclaimvariability.Thecourtsarethereforelikelytocertifysuchaclass.
37Letusfornowignorecomplexitiesassociatedwithstatisticalindependence.
38Wecanimagineasingletrialbefore10independentjuries;butitisbettertoimaginethecasebeinglitigatedanewbeforeeachofthe10 juries,since judgmentvariabilityarises fromvariability in litigation(e.g., inthepresentationofevidence)aswellasjuryvariability.
24
outcomeofthefirstcase.Byapplyingthisaggregatedoutcome,ratherthananysingle
verdict,wemayreducetheerrorresultingfromjudgmentvariabilitytonearlynothing.39
Applyingthisreplicationproceduretoallmillionclaimswouldbeincredibly
costly—perhapsfarmorecostlythancanbejustifiedbythebenefitsoftheprocedure—but
thepurposeofthehypotheticalissimplytomakethepointthatreplicationallowsusto
reduceerrorassociatedwithjudgmentvariability.
Now,inthecontextofasingleclaim,thebenefitsofthecostlyreplicationprocedure
arerelativelylow,sincetheerrorresultingfromjudgmentvariabilityislowinthefirst
place,asitistheerrorassociatedwithonlyasingleclaim.Similarly,applyingreplicationto
eachandeveryclaiminthehypotheticalsetof1millionclaimsdescribedaboveis
incrediblycostlyandimpractical;andinfactcanbeviewedjustasweviewreplicationina
singleclaim,but1milliontimes.
Amazingly,however,inthecontextofahomogeneousclass,wedonotneedtoapply
replicationtoeachandeveryclaiminordertorealizethebenefitsofsuchreplication.In
fact,assumingthattheclaimsarehomogeneous,wecanapplythereplicationprocedurea
singletime—eitherlitigatingasingleclaim,e.g.,before10independentjuries,orby
litigating10claims,eachbeforeanindependentjury40—andrealizetheerror-reducing
benefitsoftheprocedureasthoughweappliedreplicationforeachclaimindividually!
39Seesupranote28,andaccompanyingtext.
40Theseproceduresareequivalent,sincetheclaimsarehomogeneous.
25
Forthisreason,theclassactioncontextmayprovideauniqueopportunitytoreduce
errorresultingfromjudgmentvariabilitywholesale—thatis,withoutincurringthe“full”
costsofsuchprocedures.Thus,ifreplicationcanbeusedtomitigatetheerrorresulting
fromjudgmentvariability,itispossiblethataggregation—andsamplingproceduresin
particular—canresultinfarmoreaccuracythaneventhepurportedidealofindividualized
litigation.41
Opponentsofsamplinghavelargelyneglectedormisunderstoodthepossibilitythat
samplingcanreducejudgmentvariabilityandtherebyincreaseaccuracyinthelaw.For
example,ProfessorRobertBone,commentingonSaksandBlanck′sreasoningregarding
theutilityofsamplingasafunctionofclaimvariability,42statesthatthe“problemwith
[their]argumentiseasytosee,”remarkingthatifclaimswerehomogeneous,thensampling
wouldbeunnecessaryinthefirstinstance.43Theauthorexplainsthat“[i]ftherewere
perfecthomogeneity,therewouldbenoproblemwithmasstortlitigationfromthepointof
viewofoutcomeaccuracy.Ifallcaseswereidentical,thenthetrialofanyonewouldbejust
asgoodasthetrialofanyother,andtheaggregationcouldbeeasilyadjudicatedwitha
41Note,dependingontheseverityofthejudgmentvariabilityassociatedwithagivensetofclaims,aggregationmaywellenhanceaccuracyevenifreplicationyieldsabiasedoutcome.Thatis,ifwerelaxtheassumptionin§3.1above,thataveragingverdictsfrominfinitelymanyrepeatedtrialswouldyieldthe“correct”outcome,orifweotherwiseassumethataggregationwithrespecttoaparticularsetofclaimsislikelytoresultinabiasedoutcome—an outcome that does not approach the “correct” outcome as we average more and moreindependentverdicts—thenaggregationmayneverthelessenhanceaccuracyifthereductioninerrorresultingfromjudgmentvariabilityexceedstheerrorresultingfromthebias.
42SeeSaks&Blanck,supranote2,at833-37.
43RobertG.Bone,StatisticalAdjudication:Rights,Justice,andUtilityinaWorldofProcessScarcity,46VanderbiltL.Rev.561,578(1993).
26
simpleclassaction.”44ButProfessorBone′sreasoningneglectstoaccountfortheerror
associatedwithjudgmentvariability.Becausejudgmentvariabilityexistsirrespectiveof
thedegreeofclaimvariability,theerrorresultingfromasimpleclassactionmaybefar
greaterthanthatresultingfromasamplingbasedaggregationapproach.
Asdiscussedfurtherbelow,homogeneityprovidesidealcircumstancesforerror-
reducingsamplingandextrapolationprocedures.Further,itisimportanttounderstand
that,withrespecttooutcomeaccuracy,homogeneitydoesnotallowforeasyadjudication
“withasimpleclassaction,”asProfessorBonesuggests.Tothecontrary,asingleclass
adjudicationforalarge,evenhomogeneous,classwillresultinajudgment-errorvaluethat
ismultipliedovertheentireclassofclaims,asillustratedinthehypotheticalabove
involving1millionclaimsagainstthelargecigarettemanufacturers.
Ofcourse,evenclaimsintheclassactioncontextarenotperfectlyhomogeneous.
Buttheerror-reducingbenefitsofsamplingdonotnecessarilyrequirehomogeneity.
Indeed,asshownbelow,whetherclaimaggregationincreasesaccuracydependson
whethertheerrorresultingfromjudgmentvariabilitydominatestheerrorassociatedwith
claimvariabilityorviceversa.45
4. AFrameworkforExaminingSamplingandAccuracyinClassAction
Litigation
44Id.at578n.48.
45SeeSaks&Blanck,supranote2,at833-37.
27
Assuggestedintheprevioussection,replicationcanserveasafundamentaltoolfor
addressingjudgmentvariability;andtheclassactioncontextmayoftenallowcourtsto
realizethebenefitsofreplicationprocedureswithoutincurringtheenormouscostssuch
proceduresnormallyentail.InCimino,forexample,thecourtsamplednumerousclaims
withineachdiseasecategorytoarriveatanaggregateddetermination,whichwouldbe
appliedtotheunlitigatedclaimswithineachcategory,respectively.Efficiencywasthe
primarypurposeoftheprocedure;butgivenacertaindegreeofhomogeneitywithineach
diseasecategory,theaggregateddeterminationshadthepotentialtobemoreaccuratethan
theindividualizeddeterminations.
Importantly,thecourtinCimino,andothercourtsemployingaggregation
procedures,areconstrainedwithrespecttotheprocedurestheymayapply.HadJudge
Parker,inCimino,believedwithconfidencethattheaggregateddeterminationsweremore
accuratethantheindividualizeddeterminations,andhadhedesignedthetrialplanwith
thesolegoalofmaximizingaccuracy—unconstrainedbyotherconsiderations—hemay
havedecidednotonlytoapplytheaggregateddeterminationstotheunlitigatedclaims,but
toapplythemtothelitigatedclaimsaswell.Thatis,basedontheassumptionthatthe
aggregateddeterminationsaremoreaccuratethanindividualizeddeterminations,in
additiontoapplyingtheaggregateddeterminationinagivendiseasecategorytothe
unlitigatedclaimsinthatcategory,JudgeParkermayhavedecidedtoreplacethe
individualizeddeterminationsinthesamplegroupofthatcategorywiththecategory′s
aggregateddetermination-theaveragedamagesawardinthatcategory.Otherwise,onlythe
28
extrapolationgroupwouldreceivetheaccuracy-enhancingbenefitsofreplication,while
thesamplegroupwouldsufferahighdegreeofjudgmentvariability.
Thus,ifacourtpresidingoveranactioninvolvingahomogeneousclasswere
unconstrainedinitsdeterminationtomaximizeaccuracy,itmay,forexample,sampleall
claimsintheclassforindividualizedlitigationandthenreplaceallindividualized
determinationsbyanaggregateddetermination.
Infact,acourtmaycontinuetoreducejudgmentvariabilitybyreplicatingbeyond
thenumberofclaimsintheclass—forexample,bylitigatingeachclaimintheclasstwice.
Replicationiscostly,however,andpresumablythecourt′sdesireforaccuracywouldbe
constrainedbylitigationcosts.
Butmoreover,courtspresidingoverclassactionsareconstrainedbylegal
considerationsextraneoustoconcernsforaccuracyorefficiency.
Inthecurrentarticle,Iassumethatacourt′sabilitytoincreaseaccuracyis
constrainedinaparticularmanner:thatis,Iassumethatacourtwillnotreplacean
individualizeddeterminationwithanaggregateddetermination.Acourtmustchoose
whethertosampleagivenclaimforindividualizedlitigationortopreserveitseligibilityto
receiveanaggregateddeterminationextrapolatedfromthesampledclaims.Thus,ifacourt
samplesaclaimforindividualizedlitigationandthedeterminationofanindividualized
verdict,itwillnotlaterreplacetheindividualizeddeterminationwithanaggregated
determination,suchasthesample-groupaverage.
29
Itisappropriatetoimposesuchaconstraint,evenassumingacourt′swillingnessto
permitsampling-basedaggregation.Whilethereisclearprecedentfortheimplementation
ofproceduresinwhicharepresentativeclaimislitigatedanditsdeterminationextendedto
otherclaims,46thereisgenerallynoprecedent(withinthecontextofsamplingorother)for
aprocedureinvolvingthereplacementofanindividualizeddeterminationwithan
aggregateddetermination.
Indeed,thereisafundamentaldistinctionbetweenextendingrepresentative
determinationstounlitigatedclaimsandreplacingindividualizedverdictswithaggregated
verdicts.Forexample,althoughsomecourtshaveheldthatadefendant′sSeventh
Amendmentrighttoajurytrialisnotviolatedbytheformer,47aprocedureinwhicha
courtreplacesindividualizedjuryverdictswithaggregatedverdictsishighlylikelytobe
violativeoftheSeventhAmendment.48AsJusticeBrandeisexplained:
[TheSeventhAmendment]doesnotprohibittheintroductionofnewmethodsfor determining what facts are actually in issue, nor does it prohibit theintroductionofnewrulesofevidence.Changes in thesemaybemade.Newdevicesmaybeusedtoadapttheancientinstitutiontopresentneedsandtomakeofitanefficientinstrumentintheadministrationofjustice.…Indeed,such changes are essential to the preservation of the right. The limitation
46 In addition to sampling procedures, the class action device itself arguably provides for a form of suchtreatment.
47See,e.g.,InreEstateofMarcosHumanRightsLitigation,910F.Supp.1460,1468-69(D.Hawai′i1995)(“Here,thejurydiddeterminethefactsofthecase,asthesubstanceoftheactionwaspresentedtothejury.Therewouldbenobenefittoeithersideinhavingtheentireclasstestifygiventherepetitionintheclaims.Rule23oftheFederalRule[s]ofCivilProceduredoesnotmandatethepresenceofeachmemberoftheclass.Therefore,bychoosingarandomsampleof137claimantsinanaggregatetrial,neithersidewasdeprivedofeventheformoftheirrighttoajurytrial.”).
48SeeParklaneHosieryCo.v.Shore,439U.S.322,345-46(1979)(Rehnquist,J.,dissenting)(cautioningagainstallowingproceduraldevicesthatinvadethe“jury′sprovince,”itsfunctionasafact-finder);BlueCrossandBlueShieldofNewJersey,Inc.v.PhilipMorris,Inc.,178F.Supp.2d198,256(E.D.N.Y.2001).
30
imposedbytheamendmentismerelythatenjoymentoftherightoftrialbyjurybenotobstructed,andthattheultimatedeterminationofissuesoffactbythejurybenotinterferedwith.49
Whereasthereisprecedentforextendingrepresentativeverdictstoaclassof
claims,replacingindividualizedverdictswithaggregateddeterminationsarguably
substitutesthejury′spowertodetermineissuesoffactwithadeterminationarrivedatby
thecourt′saggregationprocedure.
Similarreasoningmayapplywithrespecttodueprocessconcernsaswell.Even
JudgeParker—who,notwithstandingultimatereversalbytheFifthCircuit,stronglysided
withthelegalityofsamplingproceduresinCimino—implementedaplanthathighlighted
theimportanceofallocatingindividualizedawardstothesampledclaimants,inadditionto
ensuring“representativeness”ofthesampledclaims.Arguably,thesefeaturesofthetrial
planwerecriticaltodistinguishingthesamplingprocedureinCiminofromthe“lumpsum”
approachrejectedbytheFifthCircuitinInreFibreboardCorp.50
Further,problemswithverdictreplacementareexacerbatedbythefactthatacourt
willnotknowwithcertaintywhethertoattributeobservedoutcomevariabilityto
judgmentvariabilityortoclaimvariability,andthereisnoprecedentforattributing
observedoutcomevariabilitytotheformerratherthanthelatter.Indeed,dueprocess,the
SeventhAmendmentrighttojurydetermination,andcurrentnotionsofproceduraljustice
49BlueCrossandBlueShieldofNewJersey,Inc.v.PhilipMorrisUSAInc.,344F.3d211,225-26(2dCir.2003)(quotingInrePeterson,253U.S.300,309-10(1920)).
50893F.2d706(5thCir.1990).SeeCimino,751F.Supp.at664-66;Saks&Blanck,supranote2,at823-24.Thus,iftheprocedureinCiminohadnotultimatelybeenrejectedbytheFifthCircuit,thecourtwouldhaverequiredindividualizedallocationofdamageawardstosampledclaimantsnevertheless.
31
likelyrequirecourtstoattributevariabilityinverdictstothelatter,andsimilarly,likely
precludethepossibilityofreplacinganindividualizeddeterminationwithanaggregated
one-evenassumingcourts′willingnesstosampleandapplyanaggregateddeterminationto
unsampledclaims.Forexample,ifajuryawards100distinctdamageawardsto100
sampledclaimants,theSeventhAmendmentlikelyprecludestheassumptionthatsuch
variabilityisduetojudgmentvariability,ratherthantothejury′sfindingofdifferences
amongtheclaims,anditlikelyforbidsthereplacementofsuchawardswithanaggregated
determination.51
Asasidenote,rememberthatthedrivingforcebehindargumentsforaggregation
hasbeenefficiencyandameansofaddressing“challengesofthemassrepetitivewrong.”In
additiontotheargumentsabove,theconstraintservesasanaturalboundaryonacourt′s
51 See generally Blue Cross and Blue Shield of New Jersey, 178 F. Supp. 2d at 256 (“The historical recorddemonstratesthattheFramer′smainobjectiveindraftingtheSeventhAmendmentwastolimittheabilityofanappellatecourttooverturnaciviljury′sfindingoffact.Thereisnoindicationtheyintendedtoconstrainthetrialjudge′ssubstantialdiscretiontoemployappropriateproceduralmechanismsinmanagingatrialsoastoarrive at the truth—or as near to the truth as time and humankind′s limitations allow.” (citing Simon v.PhilipMorris,Inc.,200F.R.D.21,33(E.D.N.Y.2001))).Notethatcourtsthathaveapprovedsampling-basedtrialplans have consistently permitted extrapolation only with respect to the unlitigated claims—those in theextrapolationgroup—while assigning the respective individualizeddeterminations to claims in the samplegroup.See,e.g.,Hilao,103F.3dat782-87;Cimino,751F.Supp.at652-54.Itisoftenunclearwhethercourtshavedonesoduetothepossibilitythattheyhavetreatedsamplingasasecond-bestoption,tobeappliedonlywhen individualized litigation is not practicable, or because they have presumed that replacing anindividualized verdict with an aggregated determination is precluded by the Constitution and rules ofprocedure. But numerous courts and scholars have emphasized the advantages of aggregation overindividualizedlitigationinthecomplex-litigationcontext.SeeCimino,751F.Supp.at659-66.SeegenerallyBlueCrossandBlueShieldofNewJersey,Inc.,178F.Supp.2dat248,258(findingthat“[w]hen,asinthecaseatbar,theplaintiff is an entity that has suffered its injury in the aggregate, statistical evidence is notably amoreaccurate and comprehensible form of evidence thanwould be the testimony ofmillions of smokers”; andemphasizingthat“[m]anyauthoritiesdemonstratethatjuryfactfindingisenhancedbytheuseofaggregatingtechniques” and that “[t]he essential functions of the Seventh Amendment are enhanced, not limited, byprocedureswhich streamline and focus jury fact-finding.”) Further, for the reasons above, it is likely thatregardlesswhether courts view sampling as a second-best strategy, theywouldbeunwilling to replace anindividualizedoutcomewithanaggregatedone.
32
ambitionstoreachhigherandhigherdegreesofaccuracy.Theconstraintimpliesthe
existenceofanoptimalsamplesize,withrespecttoaccuracy,asopposedtoconditions
underwhichacourtcancontinuetoincreaseaccuracybyincreasingreplication.
Thus,tointroduceaframeworkforanalyzingthecircumstancesunderwhich
aggregationcanincreasetheaccuracyoflegaloutcomes,Iwillassumeconditionsthatcan
bedescribedas“reductivesampling.”Toillustrate,supposewehaveapondofsickfish,and
ourgoalistosaveasmanyfishaspossible.Weneedto“sample”fish,andtherebyperform
testsonthem,inordertodeterminethenatureofthediseaseandhowtotreatit.Now
assume(i)thatasweincreasethenumberoffishwesample,weincreasetheaccuracyof
ourinformationregardingthenatureofthediseaseandhowtotreatit;but(ii)that
“sampling”afishrequiresthatwekillitinordertoperformtestsonit,etc.Thus,weare
presentedwithatradeoff:themorefishwesample,themoreaccurateourinformation
regardingthediseaseandhowtotreatit,butsincesamplingafishinvolveskillingit,the
morefishwesample,thefewerfishremaintotreat.Ifwesamplenofish,theywillall
eventuallycontractanddieofthedisease.Ontheotherhand,ifwesampleallofthefishin
thepond,wewillhaveahighdegreeofknowledgeofthediseaseandhowtotreatit,butwe
willhavenofishremainingtotreat!Thus,assumingcircumstancesdescribedbyreductive
sampling,inwhichsamplingaunitreduces,or(ashere)altogetherdestroys,thevalue
obtainedfromlaterextrapolationwithrespecttothatunit—forexample,treatingor
otherwiseapplyinganoperationtotheunit—leadstotheemergenceofanoptimization
33
problem:howmanyfishmustwesamplesoastobalanceourinterestsinlearninghowto
treatthediseaseontheonehandandpreservingfishtotreatontheother.
Bysampling,wepartitionthepopulationofclaimsinto(i)asamplegroup,inwhich
claimsarelitigatedandverdictsdeterminedonanindividualizedbasis;and(ii)an
extrapolationgroup,inwhichclaimsreceivetheaverageofthedeterminationsinthe
samplegroup.Themodelthereforehighlightsthetradeoffbetweentheaccuracyofthe
samplemean,ontheonehand,andthenumberofclaimsthatremainintheextrapolation
group,ontheother.
Inearliersections,Ihavehighlightedtwoformsofvariability:claim(i.e.,fact)
variabilityandjudgmentvariability.Claimvariabilitymightinclude,forexample,various
diseasetypessufferedbysmokersinaclasssuingacigarettemanufacturer.Judgment
variability,ontheotherhand,referstothevariabilityintheverdicts,holdingthefacts
acrossclaimsconstant.Asmentionedabove,judgmentvariabilitymightresultfrom
variabilityinthepresentationofevidence,variabilityinthecompositionofajuryand
variabilityintheselectionofthejudgetopresideoverthecase.
Letusbeginbyassumingthatjudgmentvariabilityisthesolesourceofvariability.
Thatis,assumethatclaimsareperfectlyhomogeneous.Thisisagoodstartingpointfor
analysisfortworeasons.First,wemayinfactobserveasignificantdegreeofclaim
homogeneityinthecontextofclassactionlawsuits.Moreover,aclassmaybesubclassified
forthepurposeofcreatingahighdegreeofhomogeneitywithineachsubclass.Second,
assumingzerofactvariabilityallowsexaminationofthefulltheoreticalbenefitof
34
aggregationbeforeaddressingtheproblemofbalancingconcernsofjudgmentvariability
withthoseoffactvariability.
4.1 HomogeneousClaims
AssumewehaveaclassofNhomogeneousclaimsfromwhichwesamplenclaims.
Letµbethetruemeanoftheverdictsoverthetotalpopulationofpossibleverdicts—i.e.,
the“correct”verdict.Let𝑋"bearandomvariabledefinedbytheactualverdictinthei-th
claim,fori=1,2,3,...,n,where𝑋"~𝑁(𝜇, 𝜎)),i.i.d.Further,define𝑋+asthemeanofthe𝑋" ,
fori=1,2,3,...,n,where𝑋+~𝑁(𝜇,,-
+).52
Then,pursuanttotheabovedescription,letusrepresentthetotalerrorassociated
withallNclaimsasthefollowingsumofsquaresresidual:
𝑅 = (𝑋" − 𝜇))+
"23
+ (𝑁 − 𝑛) 𝑋+ − 𝜇 )
Note,ifallclaimsarelitigatedindividually,thenn=N,andthisexpressionsimplifies
to:
𝑅"+6"7 = (𝑋" − 𝜇))8
"23
52Note, in actuality, it is unlikely that𝑋" has a normal distribution. For example, there is a relatively highprobabilityofadamagesvalueofzero,sincethisvalueisassociatedwiththeplaintiffs′ failuretoprovethedefendant′s liability. Amixture distributionmay bemore appropriate. Regardless, let us assume a normaldistributionforpurposesofsimplicity.
35
Letusnowsolvefortheoptimalsamplesize—thatis,thesamplesizen*that
minimizestheexpectationof𝑅,andthusmaximizes,onaverage,theaccuracyofthetotal
legaloutcome.
TheexpectationofRcanbederivedasfollows:
𝐸 𝑅 = 𝐸 (𝑋" − 𝜇))+
"23
+ 𝑁 − 𝑛 𝑋+ − 𝜇 )
= 𝑛𝜎) + 𝑁 − 𝑛𝜎)
𝑛
≡ 𝑓 𝑛
Now,tofindtheminimizingcondition,letussolve6<(+)6+
= 0.
min+𝑓 𝑛 ⇔
𝑑𝑓(𝑛)𝑑𝑛 =
𝑑𝑑𝑛 𝑛𝜎) + 𝑁 − 𝑛
𝜎)
𝑛 = 0
⇔ 𝑛 = 𝑁
Thus,onaverage,weminimize𝑅,andmaximizetheaccuracyoflegaloutcomes,by
setting𝑛∗ = 𝑁.Therefore,wemaximizeaccuracynotbylitigatingeachoftheclaims
individually,butratherbysamplingandindividuallylitigating𝑛∗ = 𝑁claims,and
applyingthesamplemean𝑋+∗asthelegaloutcomeinallclaimsintheextrapolationgroup.
Letusnowrelaxtheassumptionofhomogeneousclaimsinordertoexaminethe
constraintthatclaimvariabilityplacesonthebenefitsofsampling.
4.2 HeterogeneousClaims
Letusbeginbynotingthattheanalysisaboveallowsustoidentifyboundsonthe
optimalsamplingofclaimswithrespecttoclaimvariability.Specifically,under
36
circumstancesofzeroclaimvariability,ourresultundertheassumptionofhomogeneous
claimsapplies:wemaximizetheaccuracyoflegaloutcomesbysampling 𝑁claims.Onthe
otherhand,ifclaimvariabilityislarge,thenouroptimalsamplesizeisN.Thus,under
circumstancesofheterogeneousclaims,theoptimalsamplesizewillfallbetween 𝑁and
N.
Letusdevelopahierarchicalmodeltodeterminewherewithintheseboundsthe
optimalsamplesizefalls.Asbefore,assumewehaveaclassofNclaimsfromwhichwe
samplenclaims.Now,however,let𝜇" bethetruemeanoftheverdictsoverthetotal
populationofpossibleverdictsinthei-thclaim—i.e.,the“correct”verdictinthei-thclaim.
Thus,asopposedtocircumstancesofclaimhomogeneity,whereasingleµwasusedto
representthecorrectverdictinallNclaims,herewemustdefineasetofterms,
𝜇3, 𝜇), … , 𝜇8,torepresentthetruemean—the“correct”verdict—foreachoftheNclaims.
Let𝑋" bearandomvariabledefinedbytheactualverdictinthei-thclaim,fori=1,2,
3,...,n,where𝑋"~𝑁(𝜇", 𝜎)),independent.Let𝜇"bearandomvariabledefinedasthetrue
meaninthei-thclaim,where𝜇"~𝑁(𝜇, 𝜏)),i.i.d.Anddefine𝑋+asthemeanofthe𝑋" ,fori=
1,2,3,...,n,where𝑋+~𝑁(𝜇, 𝜎) + 𝜏)).
Then,pursuanttotheabovedescription,letusrepresentthetotalmeasurement
errorassociatedwithallNclaimswiththefollowinglossfunction:
𝑅 = (𝑋" − 𝜇"))+
"23
+ 𝑋+ − 𝜇F)
8
F2+G3
37
Itisimportanttoobtainagoodestimateofthedistributionofthe𝜇" ’s.Letusnow
assume,however,thatthe𝜇" ’sfollowanormaldistributionasdefinedabove.
Asbefore,wecanobtaintheoptimalsamplesizebysettingthefirstderivativeofthe
expectationoftheabovelossfunctiontozero.Wethusfindthattheoptimalsamplesize
undercircumstancesofheterogeneousclaimsandjudgmentvariabilityis
𝑛∗ = 𝑁1 + 𝜆)
1 − 𝜆)
where𝜆) = J-
,-.
Thisresultisintuitive.Considerthefollowingthreescenarios.First,ifthelevelof
claimheterogeneityiszero(τ2=0),then𝜆) = 0and𝑛∗ = 𝑁,theresultobtainedfromour
optimizationundercircumstancesofhomogeneousclaimsabove.Second,if𝜏) ≥ 𝜎),then
𝜆) ≥ 1and𝑛∗ = 𝑁.Third,if0 < 𝜆) < 1,and𝜏) < 𝜎),then𝑛∗ = 𝑁 3GM-
3NM-.
5. Discussion
Thecurrentsectionintroducesanumberofadditionaltopicsfordiscussionand
futureresearch.Specifically,Iintroducepossibilitiesforparameterestimation,sequential
sampling,stratificationandanumberofconsiderationsregardingincentivestoinitiate
claimsandtosettle.
5.1 ParameterEstimation
Thecurrentarticleisintendedtointroduceaframeworkforconsideringaccuracyin
thelaw,andinparticular,theconditionsunderwhichsampling-basedaggregationcan
increaseaccuracy.Itspurposeisnot,ingeneral,tomakenormativestatementsregarding
38
whetherorhowtoapplysamplinginagivencase.However,centraltoanypractical
implementationoftheframeworkintroducedhereinistheabilitytoestimatethejudgment
andclaimvariabilityparameters.Itisbeyondthescopeofthisarticletoaddressparameter
estimationindetail,butinthecurrentsection,Ihighlightanumberofimportant
considerations.
First,itisnotnecessarilythecasethatpracticalapplicationoftheframework
requiresapreciseestimationof,orevenassignmentofnumericalvaluesto,thevariability
parameters.Asshownabove,whenasetofclaimsishomogeneous(orapproximately
homogeneous),theoptimalsamplesizeisnotafunctionofvariability—itisthesquareroot
ofthenumberofclaims,regardlessthevalueofjudgmentvariability.Further,evenin
circumstancesinwhichtheclaimsarenotapproximatelyhomogeneous,theimportant
measurementistheratioofclaimvariabilitytojudgmentvariability—thatis,therelative
valueofclaimvariabilitywithrespecttojudgmentvariability.
Thus,asafirstcourseofaction,acourtcanattempttoidentifythesourcesofclaim
variabilityintheclassofclaims,andcan“reduce”suchvariabilitythroughstratification—
thatis,bybreakingtheclassintomultiplesubclasses.AsinCimino,discussedabove,acourt
maybeabletocreatemultiplerelativelyhomogeneoussubclassesratherthanasingle
heterogeneousclass.Idiscussstratificationfurtherbelow.
Atsomepointofstratification,orperhapsevenwithoutstratification,acourtmay
beableto“eyeball”therelativelevelofclaimvariability,andavoidtheneedforformal
estimationaltogether.Inasense,courtsalreadyanalyzethevariabilityofclaimsinthe
39
courseofthecertificationphaseoflitigation—forexample,intheiranalysisof
“commonality.”
Second,ifweareinterestedinfindingmoreaccurateestimatesofthemodel′s
variabilityparameters,wehaveanumberofoptions.Itispossiblethatwithinacertain
populationofindividuals(e.g.,individualsinagivengeographicregion),juryvariability—
likelyaverysignificantsourceofjudgmentvariability—issimilarfromcasetocase.In
otherwords,itmaynotbenecessarytostudyjudgmentvariabilitywithinanyparticular
classactionlawsuit.Instead,viewingjudgmentvariabilityasarandomvariable,itmaybe
possibletounderstandthedistributionofsuchvariabilitywithinagivengeographicregion
andcategoryofclaims.Thisisanimportantareaforfutureresearch.
Wecanofcourseobtainestimatesofjuryvariability,andevenofjudgment
variability,bylitigatingasingleclaimmultipletimes.Thiscanbedonewithinthecontextof
agivenclassaction,orsimplyinthecontextofasingleclaim,ormultiplesingleclaims
withinagivengeographicregion,inordertostudythedistributionofjudgmentvariability.
Asdiscussedabove,replicationiscostly;butitmaybedeemedworthwhileinlightofthe
potentialbenefitsofsampling.Further,judgmentvariabilitycanbeestimatedusingeither
simulatedlegaltrialsorperhapsasetofexistingcases.
Estimatingclaimvariabilityisinsomesensemorecomplexthanestimating
judgmentvariability.Buttwopossibilitiescometomind.First,anareaforfutureresearch
isthepossibilityofcategorizingpastlegalclaims,andundertakingastatisticalexamination
40
ofclaimvariabilitywithinsuchcategories.Thisresearchcanbeusedtoformulateclaim-
variabilityestimatesforfutureclaims.
Second,andperhapsmoresignificantly,courtscanaddresstheissueofestimating
claimvariabilitythroughsequentialsampling,whichIaddressinthefollowingsubsection.
5.2 SequentialSampling
Thesamplingframeworkintroducedaboveassumesthatwedesignateasamplesize
priortobeginningthesamplingprocedure.Forexample,underconditionsofhomogeneous
claims,wedecideupfrontthatwewillinclude 𝑁claimsinthesamplegroup,and𝑁 − 𝑁
claimsintheextrapolationgroup.Underconditionsofheterogeneousclaims,weinclude
𝑛∗ = 𝑁 3GM-
3NM-inthesamplegroup,and𝑁 − 𝑛∗claimsintheextrapolationgroup.
Asequentialsamplingprocedure,ontheotherhand,allowsustobeginbytakinga
smallsample,andthentousethissampletoestimaterelevantparameterspriorto
determiningamoregeneralsamplesize.Infact,wearenotrestrictedtoatwo-tier
samplingapproach.Wecanrepeatedlytakesmallsamples,anditerativelyupdateour
estimates.
Inparticular,acourtcanapplysequentialsamplingasfollows:(i)estimate
judgmentvariabilitythrough,forexample,oneoftheproceduresdiscussedabove;(ii)
estimateaprobabilitydistributionfortheclaimvariabilityparameterandchooseasample
sizepursuanttotheestimateandthesequentialsamplingplan;(iii)updatetheestimate
pursuanttotheclaimvariabilitydatainthesample,and,ifnecessary,takeafurthersample
pursuanttothenewestimate;and(iv)repeatstepthree.
41
Byfixingajudgmentvariabilityestimateupfront,wecanestimateclaimvariability
inthefirstsamplesimplybycomputingthesamplevarianceoftheoutcomesandadjusting
forjudgmentvariability.
Theparticularsofconstructingasequentialsamplingschemearebeyondthescope
ofthisarticle.Butnotethatitisimportantthattheschemeisconstructedsoastomaintain
independenceamongtheclaimoutcomes,whichmayinvolvecertainadditionalcosts.
Further,sequentialsamplinginvolvessomecommitmenttosamplinginthefirst
instance.Acourt,however,canimplementasequential-samplingprocedureincombination
withmethodsdiscussedintheParameterEstimationsectionabove.Forexample,acourt
mayusestratificationorsimply“eyeballing”toestimatethattheclassisbelowacertain
levelofheterogeneity—andtochooseaninitialestimatefortheclaimvariability
parameter.Thenthecourtcanchooseasamplesizeaccordingly.
Forexample,acourtmaybegininstageonebyassumingthataclassis
approximatelyhomogeneous,andthereforechooseasamplegroupofsize𝑛OPQPRS+PTU∗ =
𝑁,anoptimalsamplesizethatdoesnotdependonvariabilityparameters.Oncetheclaims
inthesamplegrouphavebeenindividuallylitigated,thecourtmayobtainanestimateof
theclaimvariability.53Now,sincethecourthasobtainedestimatesofclaimvariabilityand
judgmentvariability,itcanrelaxtheassumptionofhomogeneousclaims,andcompute
53Assumingwecanobtainareasonableestimateof judgmentvariabilityasdiscussedabove, thecourtmayobtain an estimate of claim variability simply by computing the variability of sample group outcomes andsubtractingoutthevariabilityattributabletojudgmentvariability.
42
𝑛∗ = 𝑁 3GM-
3NM-,themore-generaloptimalsamplesize.Ifthiscomputationresultsina
samplesizethatexceedsthesizeofthestage-onesamplegroup,thenthecourtwillsample
anadditional𝑛∗ − 𝑛OPQPRS+PTU∗ claimsforlitigation.Finally,oncethecourthaslitigatedn*
claimsandreceivedindividualizeddeterminationsfortheseclaims,itwillassignthemean
ofthesedeterminations,𝑋+∗ ,toallremainingclaims—theclaimscontainedinthe
extrapolationgroup.
5.3 Stratification
Theutilityofsamplingisassociatedwiththelevelofhomogeneityoftheclass.Atthe
extremes,aclassofperfectlyhomogeneousclaimsallowsforanoptimalsamplesizeof
𝑛OPQPRS+PTU∗ = 𝑁,whilecircumstancesunderwhichclaimheterogeneityishighand
judgmentvariabilityislowaltogetherdestroythevalueofextrapolatingfromthesample
group—thatis,suchconditionsinvolveanoptimalsamplesizeofN.Thus,tosimplifythe
problemandmaximizetheeffectivenessofclaimaggregation,acourtcanstratifya
heterogeneousclassofclaims,therebycreatingmultiplesmaller,butrelatively
homogeneous,classes.54Throughstratification,thecourtcan“control”forsignificant
sourcesofvariability,andthereby“modify”thefunctionalvariabilityoftheclaims,and
achievealevelofefficiencyandaccuracythatisotherwisenotpossible.
Asasimpleexample,assumethat5,000smokerclaimscanbedistinguishedfrom
oneanotheronlyonthebasisofthetypeofdamagessuffered.One-fifthoftheplaintiffs
54SeegenerallyCimino,751F.Supp.at649;Saks&Blanck,supranote2,at842.
43
sufferedfromheartdisease,one-fifthsufferedfromlungdisease,one-fifthsufferedmerely
fromoverpaying,etc.Assume,forsimplicity,nooverlapamongthecategories.Ratherthan
samplingfromtheentireclassof5,000claims𝑛∗ = 𝑁 3GM-
3NM-claims—arelativelylarge
samplesize,ifnotthesizeoftheentire5,000-claimclassaltogether—thecourtcancreate
five1,000-claimhomogeneousclasses,fromwhichitwillsample𝑛"∗ = 𝑁claimsfrom
each(whereiisanindexforsubclasses1…5).Thus,intotal,thecourtwillsample5( 𝑁)
claims;but,asinCimino,itwillusethe𝑛3∗ = 𝑁3claimstoextrapolatedeterminationsfor
thefirstsubclass,the𝑛)∗ = 𝑁)claimstoextrapolatedeterminationsforthesecond
subclass,andsoon.
Aninterestingtopicforfutureresearchistheproblemofoptimalstratification—i.e.,
thenumberofstrata—undervariousvariabilityconditions.
5.4 IncentivestoInitiateClaimsandtoSettle
Asmentionedabove,itisnotmyaiminthecurrentarticletomakenormative
determinationswithrespecttotheimplementationofclaim-aggregationprocedures.
However,animportantconsiderationforlawmakersisthewayinwhichsuchascheme
mightaffectincentivestoinitiateactions,aswellasincentivestosettleclaims(ratherthan
litigate),giventhatanactionhasbeeninitiated.
Atfirstglance,onemightthinkthatclaimaggregationmayhaveanegativeeffect,
withrespecttosocialobjectives,onincentivesofpotentiallitigantstoinitiateclaims.
Specifically,withinagivenclassofclaims,potentiallitigantswithweakerclaims(i.e.,claims
involvingalowerexpectedrecovery)maybeoverincentivizedtojoinaclassgovernedbya
44
procedureinvolvingaggregationofclaims,whilepotentiallitigantswithstrongerclaims
maybeunderincentivizedtojoinsuchaclass.Thisisbecauseclaimaggregationinvolvesa
substantialpossibilitythatagivenlitigantwillbechosenfortheextrapolationgroup,in
whichcase,shewillreceivethemeandeterminationinthesamplegroupratherthanan
individualizeddetermination.
Therearenumerousproblemswiththisreasoning;andtotheextentthatincentives
arenecessarilyaffected,courtsmaybeabletoaddresssucheffectsatarelativelylowcost.
First,totheextentthat“weaker”plaintiffsareoverincentivizedtojoinaclassunderthe
aggregationscheme,itisnotdissimilartotheoverincentiveproducedbythecurrentclass
actionframework,whereinaverdictassociatedwith“representative”claimsisappliedto
theentireclass.Ofcourse,acourtmayorderaparticularprocedure,suchasindividualized
hearings,fordeterminingtheallocationofthetotalawardamongtheclaimants;butsucha
procedureisentirelyconsistentwiththeaggregationschemeaswell.Forexample,acourt
mayemploysamplingforthepurposeofarrivingataclasswideliabilityordamages
determination,butthereaftermayimposeafurtherprocedurefordeterminingthe
allocationofthedamagesaward.
Underboththecurrentclassactionframeworkandasamplingframework,courts
mayavoidundesirableincentivesbydeterminingthataclassistooheterogeneous,thus
refusingtocertifytheclassforclassactionlitigation.Further,acourtmayseektostratify
theclassinthefirstinstanceandtherebycreaterelativelyhomogeneoussubclasses.Inthis
way,theweakerlitigantsarenotoverincentivized,andthestrongerlitigantsarenot
45
underincentivized,tojointheclass.Eachcategoryoflitigantswouldexpecttobegrouped
withothersimilarly-situatedlitigants.
Additionally,itiswellrecognizedthatsamplingoffersthepotentialforenormous
costsavings,andtotheextentthataggregationallowsforincreasedaccuracyand
reductionsinlitigationcosts,incentivestolitigateclaimstherebybecomemorealigned
withsocialobjectives.55Assertionsthatsamplingincreasessocialcostsbyburdeningthe
courtsystemwithnumerousbellwethertrialsareflawed.Suchassertionsarebasedonthe
assumptionthat,ifacourtrefusestocertifyaproposedclass,themembersoftheclasswill
treattherulingasagenerallossandwillnotbringtheirclaimsindividually.Totheextent
thatthisisinfactthecase(itoftenis),closingthecourt′sdoorsonlitigantswithvalid
claimscertainlyshouldnotbeunderstoodasasocialvictory.Tothecontrary,itrepresents
afailureofthejudicialsystem,andthesocialcostsofsuchfailures—including,forexample,
theharmfulincentivestructureestablishedbyallowingmasstortfeasorstoavoid
liability—arelikelytofaroutweighthelitigationcostsofsampling.56
55Thisapplieswhethersocialobjectivesrelate,forexample,toconcernsofdeterrenceorconcernsoffairness.
56SeegenerallyBlueCrossandBlueShieldofNewJersey,Inc.,178F.Supp.2dat247-48(“Inmassexposurecaseswithhundredsofthousandsormillionsofinjured...thecostofsuchone-on-oneproceduresisinsuperableandunsuitableforeitherajuryorabenchtrial.Theconsequenceofrequiringindividualprooffromeachsmokerwouldbetoallowdefendantswhohaveinjuredmillionsofpeopleandcausedbillionsofdollarsindamages,toescapeallliability.”);DavidRosenberg,TheCausalConnectioninMassExposureCases:A“PublicLaw”VisionoftheTortSystem,97HARV.L.REV.849(1984);DavidRosenberg,IndividualJusticeandCollectivizingRisk-BasedClaims inMass-ExposureCases, 71N.Y.U.L.REV. 210 (1996).Note, to the extent that itmaybe argued thatsamplingproceduresallowforincreasedaccuracyandshouldthereforeoccurevenwhensuchproceduresarenot required tomaintain a class action, sampling arguably results in heightened litigation costs—e.g., fromlitigating 𝑁 claimsrather thanasingleclaim—andwill thereforeaffect incentives to litigateandtosettle.Claimantsmaybelesswillingtobringclaims,andclaimantsanddefendantsmoreeagertosettlemattersoutofcourt,toavoidtherelativelyhighcostsoflitigation.Itmaybeargued,however,thatthecostsofjudgmentvariability,andtheinaccuracythatresultstherefrom,outweighanyincreaseinlitigationcost,includingalteredincentiveswithrespectto litigationandsettlement.That is,currentclassactionprocedures,whereasingletrial—subject to a high degree of judgment variability—can possibly determinewholesale the outcome of
46
Further,aggregationproceduresmaybedesignedtoencouragesettlementamong
theparties.Indeed,theuseofbellwethertrialsforpurposesoffacilitatingsettlementand
theresolutionofclaimsiswellrecognized.AstheFifthCircuitremarkedinInreChevron
U.S.A.,Inc.,“Thenotionthatthetrialofsomemembersofalargegroupofclaimantsmay
provideabasisforenhancingprospectsofsettlementorforresolvingcommonissuesor
claimsisasoundonethathasachievedgeneralacceptancebybothbenchandbar.”57
Forexample,acourtmayoptforaframeworkinwhichsampledclaimsarelitigated
instages.Thisnotonlyallowsforcalibrationofsamplingprocedures,asdescribedabove,
butalsoallowsthepartiestocalibratetheirexpectationswithrespecttotheoutcomeofthe
litigation,thusfacilitatingsettlement.TheFifthCircuitexplained,“Thereasonsfor
acceptancebybenchandbarareapparent.Ifarepresentativegroupofclaimantsaretried
toverdict,theresultsofsuchtrialscanbebeneficialforlitigantswhodesiretosettlesuch
claimsbyprovidinginformationonthevalueofthecasesasreflectedbythejury
verdicts.”58
thousands,orevenmillions,ofclaimsarguablyentailfargreatercoststhanthoseassociatedwithlitigatingtheclaims contained in the sample group. Future research should examine ways in which courts can takeadvantage of economies of scale to reduce litigation costs associated with sampling. Additionally, futureresearchshouldinvestigatetheeffectsonincentivestoinitiateclaimsandsettlesuitsafteraccountingfortheroleoflawfirmsandcontingencyfeesinparticular.Itispossiblethatsucheffectsaremitigatedafteraccountingforfirms′willingnesstoincurtheriskassociatedwithlawsuitsinexchangeforlargerpotentialpayoffs.Itisalsopossiblethatthecostsassociatedwithaggregationcombinedwiththeresultingincreasesinaccuracymayin fact result in a reduction in frivolous or otherwise undesirable litigation. In any event, it shouldnotbeassumed thata claimant in thesamplegroupwould incurcostsbeyond those incurredbyclaimants in theextrapolationgroup; such costs canbe spreadacross the class, if the class (rather than,e.g., a law firm) isincurringthecostsoflitigationinthefirstinstance.
57109F.3d at1019 (highlighting reference tobellwether trials in theManual forComplexLitigation, citingManualforComplexLitigation§33.27-.28(3ded.1995)).SeegenerallyFallonetal.,supranote12,at2323.
58InreChevronU.S.A.,Inc.,109F.3dat1019;seealsoConnecticutCoolingTotalAir,Inc.v.ConnecticutNaturalGasCorp.,46Conn.Supp.82,89(Conn.Super.Ct.1999)(“Thecourthasdevisedacasemanagementstrategy
47
Adefendantcorporationthatobservesconsistentlossesinthefirststageof
samplingmaydecidetobendtotheplaintiffs′settlementdemands.Similarly,aplaintiff
classthatobservesconsistentlossesmaydecidetodropfurtheractionaltogether.Between
thesetwoextremes,thepartiescancalibratetheirexpectationsandtheirdemands,and
therebyenhancethelikelihoodofsettlingafterperhapstheinitialstageoflitigation.
6. Conclusion
Courtsandauthorshavesuggestedthat,undercertaincircumstances,sampling
procedurescannotonlyincreaseefficiency,butaccuracyaswell.SaksandBlanck,aswell
asotherauthors,havehighlightedtheroleofwhatIhavereferredtoas“judgement
variability”inthelaw,andtheabilitytoemploysamplingprocedurestoreducesuch
variabilityandtherebyreduceerrorinthelaw.Suchassertionshavebeenusedtorebut
anti-aggregationargumentsthatarebasedonthepremisethataccuracycannotbe
sacrificedforthesakeofefficiency.
Butunderwhatcircumstancesinparticularcansamplingproceduresincrease
accuracy?Whataretheconditionsunderwhichsamplingwillresultinanetreduction—
accountingforeffectsofbothjudgmentvariabilityandclaimvariability—oferrorinthe
law?Assertionsthatsamplingprocedurescanincreaseaccuracyhavebeenmetwith
skepticismandageneralunwillingnesstorelyonsuchassertionsinreal-worldcontexts.
Suchskepticismisarguablyduetothefactthatlegalscholarshiphasnotbegunto
involvingtrialofa‘bellwether’casefromamongthesecases,asapotentialmeansofachievingamoreprompttrialofissuesthatmayleadtonegotiatedresolutionsofallthecases.”).SeegenerallyCimino,751F.Supp.at649.
48
contemplate,inanyrigorousform,thepracticaleffectofsamplingproceduresonaccuracy
underreal-worldconditionsofbothclaimandjudgmentvariability,andwithrealistic
constraintsimposedbythelaw.
Inthecurrentarticle,Ihaveintroducedaframeworkforexaminingtheconditions
underwhichsamplingcanincreaseaccuracyinthelaw.Inparticular,Ihaveintroduceda
simplemodelforstudyingtheeffectsofsamplingonaccuracy,andforderivingtheoptimal
samplesize,withrespecttoaccuracy,underconditionsofclaimandjudgmentvariability,
andwithconstraintsdescribedbyreductivesampling.Ihavealsointroducedanumberof
importantconsiderationsandtopicsforfutureresearch.Specifically,Ihavediscussed
possibilitiesforestimatingvariabilityparametersandtheuseofsequentialsampling,the
potentialforstratificationproceduresthatmayallowcourtstoreducethedegreeofclaim
heterogeneityandtherebyincreasetheutilityofclaimaggregation,andconsiderations
relatedtoincentivestoinitiateclaimsandtosettleundercircumstancesofclaim
aggregation.
Myaiminthecurrentarticlewastobuildonpreviousliteraturetointroducea
frameworkanddiscussionforconsideringtheconditionsunderwhichsamplingcan
increaseaccuracyinthelaw.Myhopeisthatthearticlewillserveasafirststeptowarda
morerigorousexaminationofsuchconditions,andultimatelythepracticalimplementation
ofsamplingtoincreaseaccuracy,aswellasefficiency,inthelaw.
49
II. SamplingandReliabilityinClassActionLitigation*
Courtscontinuetostrugglewiththelimitsofstatisticalsamplinginresolvingclaims
arisingfrom“themassrepetitivewrong.”1InCiminov.RaymarkIndus.,Inc.,a1990asbestos
classaction,U.S.DistrictCourtJudgeRobertParkerdividedaclassof2,298claimantsinto
fivesubclassesbasedonclaimedinjuries,andselectedarandomsamplefromeach
subclasstoformarepresentativesamplegroupof160claimants.2Hesubmittedthesample
group’sclaimstoajuryforindividualdeterminationsandthenextrapolatedoutcomesfor
thenon-sampledclaimsbyapplyingtheaveragesamplegroupdeterminationstoeach
subclass,respectively.3TheFifthCircuitultimatelyrejectedJudgeParker’ssampling
procedureonconstitutionalgrounds.4
Inrecentyears,courtsandcommentatorshavecriticizedtheuseofsamplingto
proveclasswideliabilityanddamages.5Itiswidelybelievedthatsamplingservesgoalsof
*Thisarticleoriginallyappearedin2016CARD.L.REV.DENOVO207(2016).Citation:HillelJ.Bavli,SamplingandReliabilityinClassActionLitigation,2016CARD.L.REV.DENOVO207(2016).Itmayhavebeenmodifiedfromitsoriginalformforpurposesofconsistency.TheauthorthanksJohnKennethFelterandtheCardozoLawReviewEditorialBoardfortheirhelpfulcommentsandedits.
1Ciminov.RaymarkIndus.,Inc.,751F.Supp.649,652(E.D.Tex.1990)(citingHERBERTB.NEWBERG,NEWBERGONCLASSACTIONS§17.06,at373(2ded.1985)).
2Id.at652–54;seealsoHillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation,14LAW,PROBABILITY&RISK67,68(2015)[hereinafterAggregatingforAccuracy].
3AggregatingforAccuracy,supranote2,at68.
4SeeCiminov.RaymarkIndus.,Inc.,151F.3d297(5thCir.1998).
5See,e.g.,Wal-MartStores,Inc.v.Dukes,131S.Ct.2541,2561(2011).
50
efficiency,butonlyatthecostofreliability—andthatthe“benefitsofefficiencycannever
bepurchasedatthecostoffairness.”6
Ina1992StanfordLawReviewarticle,ProfessorsMichaelSaksandPeterBlanck
arguedthatsampling,whenperformedcorrectly,notonlysatisfiesthestandardsof
reliabilityachievablethroughindividuallitigation,butthatsamplingcanalsoincreasethe
reliabilityoflegaloutcomes.7
However,courtshavegenerallybeenunwillingtoacceptthereliabilityofsampling
proceduresusedtoproveclasswideliabilityanddamages;andcourtsfrequentlyreject
samplingonconstitutionalandproceduralgrounds.8But,asSaksandBlanckhaveasserted,
“amajor—perhapsthemajor—dueprocessconcerninanaggregatedtrialisthevalidityof
theoutcome.”9Moreover,“[t]hemainargumentagainsttrialbyaggregationandsampling
assertsthatsuchtrialscannotgivethepartiesasaccuratearesultastheywouldobtain
throughtraditionalbilateraltrials.”10
6Malcolmv.Nat’lGypsumCo.,995F.2d346,350(2dCir.1993);seealsoInreChevronU.S.A.,Inc.,109F.3d1016,1023(5thCir.1997)(Jones,J.,concurring).
7MichaelJ.Saks&PeterDavidBlanck,JusticeImproved:TheUnrecognizedBenefitsofAggregationandSamplingintheTrialofMassTorts,44STAN.L.REV.815,815–19(1992).
8SeeWal-MartStores,Inc.,131S.Ct.at2561;seealsoOrtizv.FibreboardCorp.,527U.S.815,845(1999)(citingAmchemProd.,Inc.v.Windsor,521U.S.591,613(1997)).
9Saks&Blanck,supranote7,at833(emphasisinoriginal);seealsoJointAnti-FascistRefugeeComm.v.McGrath,341U.S.123,171–72(1951)(Frankfurter,J.,concurring);MartinH.Redish&LawrenceC.Marshall,AdjudicatoryIndependenceandtheValuesofProceduralDueProcess,95YALEL.J.455,476–77(1986).
10Saks&Blanck,supranote7,at833;seealsoInreChevronU.S.A.,Inc.,109F.3dat1020(“[O]urproceduraldueprocessconcernsfocusonthefactthattheprocedureembodiedinthedistrictcourt’strialplanisdevoidofsafeguardsdesignedtoensurethattheclaimsagainstChevronofthenon-representedplaintiffsastheyrelatetoliabilityorcausationaredeterminedinaproceedingthatisreasonablycalculatedtoreflecttheresultsthatwouldbeobtainedifthoseclaimswereactuallytried.”).
51
Thequestionremains:whyhavecourtsandcommentatorslargelydiscountedthe
argumentthatsamplingoffersnotonlyincreasedefficiency,butreliabilityaswell?Ina
2015paper,Iexplainthataprimarysourceofskepticismmaybethegeneralitywithwhich
theargumenthasbeenmade.11AlthoughSaksandBlanck,andothers,havesuggestedthat
samplingmayincreasethereliabilityoflegaloutcomes,theliteraturehasnotadequately
developedtheargumentorproducedaframeworktoanalyzetheeffectofsamplingon
reliability.12Indeed,samplingdoesnotinevitablyincreasethereliabilityoflegaloutcomes;
rather,itseffectonreliabilitydependsontheparticularfeaturesoftheclaims.13Therefore,
inAggregatingforAccuracy,Idevelopaformalframeworkforexaminingconditionsunder
whichsamplingcanincreasethereliabilityoflegaloutcomes.14
InthisArticle,IexplainmyconclusionsinAggregatingforAccuracyinnon-
mathematicalterms,andunderscorecertainimplicationswithrespecttoclassaction
litigationandconsiderationsinlightoftheU.S.SupremeCourt’srecentdecisioninTyson
Foods,Inc.v.Bouaphakeo.15Ibeginbydescribingthebuildingblocksofmyanalysis—the
conceptsofreliabilityandaccuracyinthelaw.
1. ReliabilityintheLaw
11AggregatingforAccuracy,supranote2,at69.
12Id.
13Id.
14Seegenerallyid.
15136S.Ct.1036(2016).
52
Assumethatforeverylegalclaimthereisa“correct”outcomethatcanbe
determinedbyapplyingthe“true”stateofthelawtothecompletefactssurroundingthe
claim.16But,intherealworld,completeknowledgeregardingthelawandthefacts
surroundingaclaimisunavailable.Consequently,alegaloutcome(resultingfromatrialor
otheradversarialproceeding)servesasanestimateofthe“correct”outcomefortheclaim.
Therefore,foreverylegalclaim,thereisanerrortermthat(althoughgenerallyunknown)
reflectsthedisparitybetweentheobservedoutcomeandthe“correct”outcome.Accuracy,
then,isdefinedintermsoftheproximityoftheobservedoutcometothe“correct”
outcome.17
Oneconvenientandarguablysensibleconceptualizationofthe“correct”outcome
associatedwithalegalclaimistheawardthatwouldresultfromcomputingthemeanof
infinitelymanyadjudicationsoftheclaimundervariousconditions(e.g.,variousjury
compositions,judges,attorneys,presentationsofevidence,etc.).18
Thus,Idefinethereliabilityofalegalprocedureastheaccuracyofthelegaloutcome
thatcanbeexpectedbyfollowingtheprocedure.Forexample,ifitisexpectedthatacertain
16Alternatively,itcanbeassumedthatthereisadistributionof“correct”outcomesassociatedwitheverylegalclaim.SeegenerallyAggregatingforAccuracy,supranote2,at69.
17Seegenerallyid.at74;JonathanJ.Koehler&DanielShaviro,VeridicalVerdicts:IncreasingVerdictAccuracyThroughtheUseofOvertlyProbabilisticEvidenceandMethods,75CORNELLL.REV.247(1990)(discussing“accuracy”).Notethataccuracycanbedefinedmoreformallyusingtheconceptsofbiasandvariance.However,anexplicitdiscussionoftheseconceptsisbeyondthescopeofthisArticle.
18SeeSaks&Blanck,supranote7,at833–34;AggregatingforAccuracy,supranote2,at74.Othermeasuresofcentraltendency,suchasthemedian,arealsopossible.Forsimplicity,throughoutthisArticleweusesolelythemean.
53
legalprocedurewillproduceahighlyaccurateoutcome—anobservedoutcomeinclose
proximitytothe“correct”outcome—theprocedureisconsideredreliable.19
Anin-depthdiscussionoftheroleofaccuracyinthelawisbeyondthescopeofthis
Article.Iassumethataccuracyisafundamentalgoalofthelaw,whethersuchgoalis
groundedinaccuracyitselforafurtheraim,suchasdeterrenceorfairness.20
2. ClaimandJudgmentVariability
Criticsofsamplinghavefocusedontheerrorthatresultsfromapplyingapoint
estimate—e.g.,theaverageofthesamplegroupoutcomes—toaclassofheterogeneous
legalclaims.21Heterogeneitycanbedescribedintermsofclaimvariability—i.e.,the
variabilityofthefactsoftheclaims,or,moreprecisely,thevariabilityofthe“correct”
outcomesassociatedwithindividualclaims.22
Butcriticsofsamplinghaveignoredasecondtypeoferror:errorresultingfrom
judgmentvariability.23Judgmentvariabilityrepresentstherandomnessassociatedwitha
claim’soutcome.Itarisesfromthevariabilityinconditionsunderwhichoutcomesare
determined,includingthecompositionofthejury,thejudgepresidingoverthecase,the
19SeeAggregatingforAccuracy,supranote2,at74–78foradetaileddiscussionofaccuracyandvariabilityinthelaw.
20Seeid.at75;Saks&Blanck,supranote7,at829(citingRedish&Marshall,supranote9,at476–77).
21AggregatingforAccuracy,supranote2,at75–76.SeegenerallySabyGhoshray,HijackedbyStatistics,RescuedbyWal-Martv.Dukes:ProbingCommonalityandDueProcessConcernsinModernClassActionLitigation,44LOY.U.CHI.L.J.467(2012).Iftherearesubclasses,thenacourtislikelytoassigntheaveragesamplegroupoutcomewithineachsubclasstothenon-sampledclaimsineachsubclass,respectively.See,e.g.,Ciminov.RaymarkIndus.,Inc.,751F.Supp.649,651–54(E.D.Tex.1990).
22AggregatingforAccuracy,supranote2,at76.
23Id.at76–78.
54
presentationofevidence,theattorneysinvolvedinthecase,etc.24Forexample,ifasingle
claimistriedtentimesindependently(eachtrialwithanewselectionoftrieroffact,
attorneys,etc.),itislikelythattherewouldbetendistinctverdicts.But,ifthereisasingle
correctoutcomeassociatedwiththeclaim,thenjudgmentvariabilityreflectserror—
disparitiesbetweentheobservedoutcomesandthe“correct”outcome.25
Forsimplicity,Iassumethat,onaverage,acasewillresultinthe“correct”
outcome—instatisticalterms,theoutcomeisunbiased.Judgmentvariabilityrepresentsthe
degreetowhichanobservedoutcomevariesaroundthe“correct”outcome.26Thereader
mayimagineabellcurvecenteredatthe“correct”outcome,wherethejudgmentvariability
determinesthewidthofthecurve.Onaverage,theoutcomewillbethe“correct”outcome;
buttheoutcomeisvariablearoundthe“correct”outcome,andsuchrandomness,
representedbyjudgmentvariability,reflectserror.27
Indeterminingappropriatestandardsintheclassactioncontext,courtsand
commentatorshavefocusedonerrorresultingfromclaimvariability,buthavegenerally
ignorederrorresultingfromjudgmentvariability.28Indeed,eventhepurportedidealof
individuallitigationproducesoutcomesthataresubjecttojudgmentvariability.
24Id.at76–77.
25SeeSaks&Blanck,supranote7;EdwardK.Cheng,When10TrialsAreBetterthan1000:AnEvidentiaryPerspectiveonTrialSampling,160U.PA.L.REV.955,958–60(2012);AggregatingforAccuracy,supranote2,at75–78.
26SeegenerallyAggregatingforAccuracy,supranote2,at75–78.
27Seeid.at75–79.Considerthemagnitudeoferrorthatresultsfromjudgmentvariabilitywhenclasswidedamagesaredeterminedbyadjudicatingasinglerepresentativeclaim.
28Id.at76–78.
55
3. ReducingJudgmentVariabilitywithSampling
Consideracostlyprocedurethroughwhichtheoutcomeofaclaimisdeterminedby
averagingtheverdictsresultingfromtenindependent“replications”ofatrial,or“repeated
adjudications”(involving,forexample,differentjudges,juries,attorneys,presentationsof
evidence,etc.).Assumingtheoutcomeisrelativelyunbiased,itiseasytoshowthat
followingthisprocedureresultsinanaccurateoutcome—anoutcomethatisclosetothe
“correct”outcome.Similarly,thisprocedurewillproduceanaccurateoutcomeforeach
claimofeachmemberofaputativeclass(orsubclass).Replicationthusincreasesthe
reliabilityoflegaloutcomesbyreducingtheerrorcausedbyjudgmentvariability.
Ontheotherhand,thecostsofsuchaprocedureareenormous,andlikelynot
justifiedbythebenefitsoftheprocedureforasingleclaim(orforeachputativeclass
member’sclaimthatrequiresapplicationoftheprocedurefortheindividualclaim).
Importantly,however,inaclassofhomogeneousclaims,itisnotnecessarytofollow
theprocedureforeachclassmember’sclaimtorealizethebenefitsoftheprocedure:
followingthereplicationprocedureforasingleclaimandextrapolatingtheresulttoall
claimsofthehomogeneousclass(orsubclass)willyieldthereliabilitybenefitsasthough
theprocedurewasfollowedforeachclaim.
Classactionsprovideopportunitiestorealizethereliabilitybenefitsofreplication
withoutincurringtheprohibitivecoststhatsuchproceduresentail.29Inparticular,courts
canusesamplingtoimprovelegaloutcomesbyreducingerrorresultingfromjudgment
29Id.at77.
56
variability.Moreover,samplingmayofferadegreeofreliabilitythatcannotbeobtained
eventhroughthepurportedidealofindividualadjudication.Further,although
homogeneityishelpful,itisnotnecessary.Asexplainedbelow,thebenefitsofsamplingina
heterogeneousclassdependonwhether,andtowhatextent,theerrorresultingfrom
judgmentvariabilitydominatestheerrorresultingfromclaimvariability.30
4. ConditionsUnderWhichSamplingCanImprovetheReliabilityofLegal
Outcomes
Above,Idescribehowrepeatedadjudicationcanincreasethereliabilityoflegal
outcomes.Assumingacertaindegreeofhomogeneity,ifacourtwereunconstrainedbycost
orlawinitspursuitofreliability,itmight“sample”alltheclaimsofaclassforindividual
adjudicationandthenreplaceallindividualoutcomeswithasingleaggregatedoutcome.In
fact,acourtcouldfurtherreducetheerrorresultingfromjudgmentvariabilityby
adjudicatingeachclaimtwice,ormoretimesforthatmatter.But,inadditiontothehigh
costsoflitigation,acourt’sabilitytoachieveextremelyreliableoutcomesisconstrainedby
law.
InAggregatingforAccuracy,Iarguethatacourtmaynotreplaceanindividualized
outcomewithanaggregatedone.31Ihighlightafundamentaldistinction,basedon
constitutionallawandrulesofcivilprocedure,betweenacourt’sauthoritytoextrapolatea
representativeclaim’sdeterminationtounadjudicatedclaimsanditsauthoritytoreplace
30Id.at78;seeSaks&Blanck,supranote7,at833–37.
31AggregatingforAccuracy,supranote2,at78–80.
57
anindividuallyadjudicatedoutcomewithanaggregatedone.32Adetaileddiscussionofthis
issueisbeyondthescopeofthisArticle.Assume,therefore,thatacourtmustchoose
betweensamplingaclaimforindividualadjudicationandpreservingtheclaimfor
assignmentofanaggregatedoutcomeextrapolatedfromthesampledclaims.33
Thisconstraintcanbemodeledusingatypeofexploration-exploitationtradeoffI
callreductivesampling,inwhichsamplingaunit—here,alegalclaim—meansreducing(or,
ashere,eliminating)itseligibilityforlaterextrapolationwithrespecttothatunit.34
InAggregatingforAccuracy,Ishowthat,usingthereductivesamplingframework
andstandardstatisticaltoolsforminimizingerror,inthecontextofaclassofhomogeneous
(orrelativelyhomogeneous)claims,accuracyismaximized,notbyadjudicatingeachofthe
claimsindividually(asisoftenviewedasideal),butratherbydeterminingindividual
outcomesforasmallrandomsampleofclaims,andassigningtheaverageofthesample
groupoutcomestotheremaining,non-sampled,claims.35Inparticular,Ishowthat,fora
classofNhomogeneousclaims,acourtmaximizesaccuracybysampling 𝑁claims,rather
thanallNclaims,forindividualadjudication.36Forexample,iftheclasscontains5,000
homogeneousclaims,acourtcanmaximizeaccuracybyrandomlysamplingabout70
32Id.
33Seeid.at80–81.
34Id.SeegenerallyHerbertRobbins,SomeAspectsoftheSequentialDesignofExperiments,58BULL.AM.MATHEMATICALSOC’Y527(1952);J.C.Gittins,BanditProcessesandDynamicAllocationIndices,41J.ROYALSTAT.SOC’Y:SERIESB(METHODOLOGICAL)148(1979).
35SeeAggregatingforAccuracy,supranote2,at81–82.
36Id.
58
claimsforindividualadjudication,assigningthe70individualoutcomestothesampled
claims,andassigningthearithmeticmeanofthe70sampleoutcomestotheremaining
4,930claims.
𝑁(orabout70intheexampleabove)isthenumberthatbalances,ontheone
hand,acourt’sinterestinobtaininginformationregardingthe“correct”outcomeofthe
homogeneousclaims(whichincreaseswithsamplesize),and,ontheotherhand,its
interestinpreservingclaimstowhichtoassigntheaccurateaggregatedoutcome.37The70
claimsinthesamplegroupreceiveindividualadjudicationsthataresubjecttosignificant
errorcausedbyjudgmentvariability,whereastheremaining4,930claimsinthe
extrapolationgroupareassignedaggregatedoutcomesthathavebeen“refined”by
repeatedadjudication—i.e.,outcomeswhosejudgmentvariabilityhasbeenreduced
significantlybyaveragingoverapproximately70repeatedadjudications.38
Now,toexaminesamplinginthecontextofheterogeneousclaims,consideran
additionalfactor:althoughthesamplingproceduredescribedabovereduceserrorcaused
byjudgmentvariability,assigningasingleaggregatedoutcome(e.g.,theaverageofthe
samplegroupadjudications)astheestimateofthe“correct”outcomesassociatedwitha
groupofheterogeneousclaims—claimsthatactuallyinvolvenumerousdistinct“correct”
outcomes—introduceserrorreflectingthedisparitiesbetweentheestimateandeachofthe
“correct”outcomes.39Thus,astheheterogeneityoftheclassincreases,thevalueof
37Seeid.at80–81.
38Id.at80–82.
39Id.at82–83.
59
assigningasingleaggregatedoutcomeastheestimateofthe“correct”outcomes
decreases.40Further,atsomedegreeofheterogeneity,thebenefitsofsampling,with
respecttojudgmentvariability,areoutweighedbythedetrimentsofsampling,withrespect
toclaimvariability.41
InAggregatingforAccuracy,Ishowthatifclaimvariabilityiszero,thentheoptimal
samplesizeis 𝑁,thehomogeneousoptimum;ifclaimvariabilityisgreaterthanjudgment
variability(e.g.,intermsofdamagesawarded),theoptimalsamplesizeisN,whichis
equivalenttoindividualadjudications;andfinally,ifjudgmentvariabilityisgreaterthan
claimvariability,thentheoptimalsamplesizeisbetween 𝑁andN,andcanbedetermined
byaparticularformula(derivedinAggregatingforAccuracy)involvingthenumberof
claimsintheclass,claimvariability,andjudgmentvariability.42
5. ImplicationsandConclusions
Theconclusionsexplainedabove,andderivedinAggregatingforAccuracy,have
importantimplicationsforacourt’streatmentofstatisticalsamplinginclassaction
litigation.Perhapsmostimportantly,acourtshouldnotassume,asmanycourtshave,that
samplingreducesreliability.Thediscussionabovemakesclearthatsamplingmayenhance
reliabilityaswellasefficiency.
Forexample,theseconclusionshaveimportantimplicationsinthecontextofclass
actionsbroughtunderRule23(b)(3)oftheFederalRulesofCivilProcedure.Inparticular,
40Id.
41Seeid.at82–83.SeegenerallySaks&Blanck,supranote7.
42SeeAggregatingforAccuracy,supranote2,at83.
60
classrepresentativeshaveproposedsamplingproceduresforpurposesoffulfillingthe
Rule’srequirementthat“thequestionsoflaworfactcommontoclassmembers
predominateoveranyquestionsaffectingonlyindividualmembers.”43Inaddressingthis
requirement,theclassrepresentativeshaveofferedsampling-basedmethodologiesatthe
classcertificationstageinattempttodemonstratethatliabilityanddamagescanbe
determinedonaclasswidebasis.44Courtsregularlyrejectsuchattempts,however,on
grounds—implicitlyorexplicitly—ofreliability.But,forthereasonsdiscussedabove,
courtsaregenerallynotjustifiedinassumingthatsamplingdiminishesreliability.
TheSupremeCourt,initsrecentdecisioninTysonFoods,Inc.v.Bouaphakeo,refused
toadopt“abroadruleagainsttheuseinclassactionsof...representativeevidence”—
specifically,evidencebasedon“arepresentativeorstatisticalsample”offeredtoestablish
classwideliability.45Instead,itheldthat“[w]hetherandwhenstatisticalevidencecanbe
usedtoestablishclasswideliabilitywilldependonthepurposeforwhichtheevidenceis
beingintroducedandon‘theelementsoftheunderlyingcauseofaction.’”46
TysonFoodsinvolvedclaimsbyTysonemployees,certifiedbythedistrictcourtasa
Rule23(b)(3)class,allegingthattheiremployer,Tyson,failedtopaycompensable
overtimewagesundertheFairLaborStandardsAct(FLSA)andIowalawfortimespent
43SeeComcastCorp.v.Behrend,133S.Ct.1426,1432(2013)(quotingFED.R.CIV.P.23(b)(3)).
44SeeComcastCorp.,133S.Ct.at1433–34;TysonFoods,Inc.v.Bouaphakeo,136S.Ct.1036,1043–44(2016).
45TysonFoods,Inc.,136S.Ct.at1046.
46Id.(quotingEricaP.JohnFund,Inc.v.HalliburtonCo.,563U.S.804,809(2011)).
61
“donninganddoffingprotectivegear.”47Thedistrictcourtsubmittedtheissuesofliability
anddamagestothejury,which“returnedaspecialverdictfindingthattimespentin
donninganddoffingprotectivegear...wascompensablework,”and“awardedtheclass
about$2.9millioninunpaidwages.”48Tysonappealed,arguing,interalia:“[T]heclass
shouldnothavebeencertifiedbecausetheprimarymethodofprovinginjuryassumedeach
employeespentthesametimedonninganddoffingprotectivegear,eventhough
differencesinthecompositionofthatgearmayhavemeantthat,infact,employeestook
differentamountsoftimetodonanddoff.”49TheEighthCircuitCourtofAppealsaffirmed
thejudgmentandtheaward.50
Inrulingthatthedistrictcourtdidnoterrincertifyingtheclass,theSupremeCourt
held:
In many cases, a representative sample is “the only practicable means tocollectandpresentrelevantdata”establishingadefendant’sliability.Manualof Complex Litigation §11.493, p. 102 (4th ed. 2004). In a case whererepresentative evidence is relevant inproving aplaintiff’s individual claim,that evidence cannot be deemed improper merely because the claim isbroughtonbehalfofaclass.TosoholdwouldignoretheRulesEnablingAct’spellucid instruction that use of the class device cannot “abridge . . . anysubstantiveright.”28U.S.C.§2072(b).51TheCourtcontinued:“Onewayforrespondentstoshow,then,thatthesample
relieduponhereisapermissiblemethodofprovingclasswideliabilityisbyshowingthat
47TysonFoods,Inc.,136S.Ct.at1042.
48Id.at1044.Notethataclassexpertrecommendedanawardofapproximately$6.7million.Id.at1052.
49Id.at1041.
50Id.at1044;Bouaphakeov.TysonFoods,Inc.,765F.3d791(8thCir.2014).
51TysonFoods,Inc.,136S.Ct.at1046.
62
eachclassmembercouldhavereliedonthatsampletoestablishliabilityifheorshehad
broughtanindividualaction.”52Itheldthat“[i]fthesamplecouldhavesustaineda
reasonablejuryfindingastohoursworkedineachemployee’sindividualaction,that
sampleisapermissiblemeansofestablishingtheemployees’hoursworkedinaclass
action.”53
TheCourtclarifieditsrulinginWal-MartStores,Inc.v.Dukes,54explainingthat“Wal-
Martdoesnotstandforthebroadpropositionthatarepresentativesampleisan
impermissiblemeansofestablishingclasswideliability.”55Wal-Martinvolvedaclassof
approximately1.5millioncurrentandformerfemaleemployeesalleginggender
discriminationunderTitleVII.56TheCourtexplainedthat“[t]heplaintiffsinWal-Martdid
notprovidesignificantproofofacommonpolicyofdiscriminationtowhicheachemployee
wassubject.”57Ultimately,theSupremeCourtrejectedplaintiffs’proposedmethodology—
proposed“asameansofovercomingth[e]absenceofacommonpolicy”58—bywhicha
sampleofclassmemberswouldbeselectedforindividualdeterminationsofliabilityand
backpay,andtheaggregateddamagesawardwouldbederivedbyextrapolatingthe
52Id.
53Id.at1046–47.TheCourtexplained:“Iftheemployeeshadproceededwith3,344individuallawsuits,eachemployeelikelywouldhavehadtointroduce[theclassexpert’s]studytoprovethehoursheorsheworked.Ratherthanabsolvingtheemployeesfromprovingindividualinjury,therepresentativeevidenceherewasapermissiblemeansofmakingthatveryshowing.”Id.at1047.
54564U.S.338(2011).
55TysonFoods,Inc.,136S.Ct.at1048.
56Id.
57Id.
58Id.
63
“numberof(presumptively)validclaims”fromthepercentageofthesampledclaims
determinedtobevalid,andthenmultiplyingthisnumberby“theaveragebackpayaward
inthesampleset.”59
TheCourtexplainedthatitsholdinginTysonFoodsis“inaccordwith”itsdecisionin
Wal-Mart:“SincetheCourtheldthattheemployeeswerenotsimilarlysituated,noneof
themcouldhaveprevailedinanindividualsuitbyrelyingondepositionsdetailingtheways
inwhichotheremployeeswerediscriminatedagainstbytheirparticularstore
managers.”60TheCourtexplainedthat“[b]yextension,iftheemployeeshadbrought1½
millionindividualsuits,therewouldbelittleornoroleforrepresentativeevidence,”and
that“[p]ermittingtheuseofthatsampleinaclassaction,therefore,wouldhaveviolated
theRulesEnablingActbygivingplaintiffsanddefendantsdifferentrightsinaclass
proceedingthantheycouldhaveassertedinanindividualaction.”61InTysonFoods,the
Courtheld:
[T]hestudyherecouldhavebeensufficienttosustainajuryfindingastohoursworkedifitwereintroducedineachemployee’sindividualaction.Whiletheexperiences of the employees inWal-Mart bore little relationship to oneanother, inthiscaseeachemployeeworkedinthesamefacility,didsimilarwork,andwaspaidunderthesamepolicy.62
59Id.(quotingWal-MartStores,Inc.v.Dukes,564U.S.338,367(2011)).
60TysonFoods,Inc.,136S.Ct.at1048.
61Id.
62Id.at1048.TheSupremeCourtheldthat,althoughthe“questionwhetheruninjuredclassmembersmayrecoverisoneofgreatimportance,”itisnot“aquestionyetfairlypresentedbythiscase,becausethedamagesawardhasnotyetbeendisbursed,nordoestherecordindicatehowitwillbedisbursed.”Id.at1050.TheCourtremandedthecaseforfurtherproceedingsconsistentwithitsopinion.Id.Significantly,ChiefJusticeRobertsexpressedconcern,inaconcurringopinionjoinedinpartbyJusticeAlito,that,sincethedistrictcourtmaybeunableto“fashionamethodforawardingdamagesonlytothoseclassmemberswhosufferedanactualinjury,”id.at1050,“itremainstobeseenwhetherthejuryverdictcanstand.”Id.at1053.Additionally,JusticeThomas,inadissentingopinionjoinedbyJusticeAlito,assertedthat“[t]heDistrictCourterredattheclasscertificationstagebyholdingthattheplaintiffssatisfiedRule23’spredominance
64
Thus,althoughtheSupremeCourtexplicitlyrefusedtoadopt“broadandcategorical
rulesgoverningtheuseofrepresentativeandstatisticalevidenceinclassactions,”the
TysonFoodsdecisionapprovestheuseofrepresentativeevidencetoestablishclasswide
liability.63
Distinguishtwotypesofsamplingmethodologiesthatputativeclassrepresentatives
haveattemptedtouseforestablishingclasswideliabilityanddamages:1)theuseof
“representativeevidence”offeredtothetrieroffactasprobativeofclasswideliability64or
damages,and2)theuseofrepresentativeadjudicationstoextrapolateoutcomesfornon-
sampled(i.e.,non-adjudicated)claims.65AlthoughtheSupremeCourtdidnotdistinguish
betweenthesetwotypesofsamplingmethodologies,itislikelythatTysonFoodsexpands
theabilityofclassrepresentativestouserepresentativeevidencetoestablishclasswide
liabilityinparticular.
Regardingtheuseofrepresentativeevidence,theCourtheld:“Arepresentativeor
statisticalsample,likeallevidence,isameanstoestablishordefendagainstliability.Its
permissibilityturnsnotontheformaproceedingtakes—beitaclassorindividualaction—
butonthedegreetowhichtheevidenceisreliableinprovingordisprovingtheelementsof
requirement.”Id.at1054.Accordingtothedissentingopinion,theissueof“whethereachemployeeworkedover40hourswithoutreceivingfullovertimepay”was“clearlyindividualized,”and,withrespecttothe“criticalissue”ofwhetherthe“individualizednatureofemployees’donninganddoffingtimesdefeatedpredominance,”id.,thedistrictcourterredbycertifyingtheclasswithoutgiving“properconsiderationtothesignificanceofvariabledonninganddoffingtimes.”Id.at1055.
63Id.at1049.
64Seeid.at1043.
65SeeAggregatingforAccuracy,supranote2,at70–72(citingcasesandliterature);see,e.g.,Ciminov.RaymarkIndus.,Inc.,751F.Supp.649,652–54(E.D.Tex.1990).
65
therelevantcauseofaction.”66TheCourt’sdecisioninTysonFoodsapprovestheuseof
statisticalsamplingtoestablishclasswideliability;buttheroleofreliabilityindetermining
whetheracourtpermitsstatisticalsamplingtoproveclasswideliabilityremainscentralto
theanalysis.
Theconclusionsexplainedabovesuggestthat,whileacourtshouldexaminethe
reliabilityofstatisticalsamplingfor,amongotherthings,methodologicalflawsandissues
relatedtothecohesivenessoftheclass,itshouldnotdiscountthereliabilityofstatistical
sampling—andrepresentativeevidenceinparticular—becauseofthesamplingitself.
Indeed,asexplainedabove,samplingmayimprovereliabilityaswellasefficiency.
Additionally,itisimportanttorealizethat,althoughthediscussionaboverelates
particularlytothereliabilitybenefitsofrepresentativeadjudications,theconclusions
generallyapplytorepresentativeevidenceaswell.Asexplained,repeatedadjudicationmay
improvereliabilitybyenablingacourt,inessence,toincorporateadditionalinformation
regardingaclassofclaims—e.g.,byaveragingovermultipleadjudicationsratherthan
relyingonasingleadjudication—andthusminimizeerrorcausedbyjudgmentvariability.
Repeatedadjudicationinaheterogeneousclasssimilarlyconfersreliabilitybenefits,aslong
astheerror-reducingbenefitsof“informationsharing”withrespecttojudgmentvariability
outweightheerror-inducingcostswithrespecttoclaimvariability.
Theuseofrepresentativeevidencesimilarlyimprovesreliability.Althoughthe
methodof“informationsharing”usingrepresentativeevidenceisdifferent—involving,for
66TysonFoods,Inc.,136S.Ct.at1046(citingFED.R.EVID.401,403,702)(emphasisadded).
66
example,theadditionalstepofprovidingtheinformationtothetrieroffact,ratherthan
incorporatingitintheoutcomedirectly(e.g.,byaveragingoverrepeatedadjudications)—
insofarasthetrieroffactincorporatestherepresentativeevidenceinitsdeterminationof
theoutcome,thereliabilitybenefitsofrepeatedadjudicationapplysimilarlytotheuseof
representativeevidence.67
TysonFoodsislikelytohaveasignificantimpactonclassactionlitigation.Putative
classrepresentativeswillbeencouragedtouserepresentativeevidencetoestablish
classwideliability,andperhapsdamagesaswell.Usingargumentsestablishing,for
example,that“eachclassmembercouldhavereliedonth[e]sampletoestablishliabilityif
67Inparticular,inAggregatingforAccuracy,anawardinaheterogeneousclassismodeledhierarchically:the“correct”awardsintheclassaredistributedaroundsomeglobalmean,whereaseachactualawardis“drawn”fromadistributionaroundeachclaim’s“correct”award.SeegenerallyAggregatingforAccuracy,supranote2,at82–83.Theformerdistributionrepresentsclaimvariability,whereasthelatterdistributionrepresentsjudgmentvariability.Inahomogeneousclass,replicationoffersaccuracybenefitsbyprovidingadditionalinformationregardingthe“correct”awardassociatedwiththereplicatedclaim,whichotherwisewouldbeobscuredbyjudgmentvariability.Inaheterogeneousclass,samplingoffersaccuracybenefits,withrespecttoacertainclaim,notbyprovidinginformationregardingthatclaim’s“correct”awarddirectly,butbyprovidinginformationregardingtheglobalmeanaroundwhichallofthe“correct”awardsaredistributed,andtherebyregardingthe“correct”awardforthesubjectclaimindirectly.Similarly,representativeevidence,suchasthetypeindisputeinTysonFoods(where,forexample,thesamplereflectsvariabilityofmeasureddonninganddoffingtimesratherthanjudgmentvariability),offersaccuracybenefits,withrespecttoacertainclaim,byprovidinginformationregardingtheglobalmeanaroundwhichthe“correct”awardsaredistributed,andtherebyregardingthe“correct”awardforthatclaiminparticular.Anotherwayofunderstandingthisisthrough“comparable-caseguidance”(CCG)methods,wherebyacourtusesinformationregardingawardsinpriorcomparablecasesasguidanceforafact-finder’sdeterminationofdamages.SeeHillelJ.Bavli,TheLogicofComparable-CaseGuidanceintheDeterminationofAwardsforPainandSufferingandPunitiveDamages,U.CIN.L.REV.(forthcoming2017)[hereinafterTheLogicofCCG].TheLogicofCCGexaminesthestatisticalmechanismbywhichCCGaffectsawards,andtheconditionsunderwhichsuchevidencewillimproveaccuracy.Inparticular,thepaperexplainsthat,undercertainmildbehavioralassumptions,theriskthatsuchevidencewouldreduceaccuracy—thaterrorresultingfromclaimvariabilityandbiaswouldoutweightheaccuracybenefitsofreducingjudgmentvariability—isminimal.Seeid.LikeCCG,representativeevidenceprovidesinformationregardingthedistributionof“correct”awardsforcomparableclaims,includingtheglobalmean,and,inturn,aboutthe“correct”awardforthesubjectclaim.
67
heorshehadbroughtanindividualaction,”putativeclassrepresentativeswillimprove
theirabilitytoestablishpredominanceunderRule23(b)(3).68
InlightofTysonFoods,acourtconsideringRule23(b)(3)certificationislikelyto
focusmoreheavilyandmoreexplicitlyonthereliabilityofrepresentativeevidenceand
statisticalsamplinggenerally.Althoughastatisticalsampleshouldbecarefullyscrutinized
todetect,amongotherthings,methodologicaldeficienciesandissuesregardingthe
cohesivenessoftheclass,samplingoftenimprovesthereliabilityoflegaloutcomes.
68TysonFoods,Inc.,136S.Ct.at1046.
68
III. TheLogicofComparable-CaseGuidanceintheDeterminationofAwards
forPainandSufferingandPunitiveDamages*
1. Introduction
Lawmakersandscholarshavestruggledtoaddresstheunpredictabilityofawards
forpainandsufferingandpunitivedamages.Jurorsareprovidedwithverylittleguidance
indeterminingsuchawards,andcourtslackobjectivestandardstoguidejurorsandreview
theirawards.Consequently,awardscanvarywildly.
Forexample,inawell-knowncaseinvolvingaclaimagainstBMWthattheauto
manufacturerhadfraudulentlysoldcarsasnewafterpaintingoverpartsthathadsuffered
corrosiondamageduetoacidrainexposurewhileintransittotheUnitedStates,an
Alabamajuryawardedthepurchasercompensatorydamagesof$4,000andpunitive
damagesintheamountof$4million.1However,inamateriallyidenticalcasebroughtby
anotherpurchaserinthesamecourtandbeforethesamejudge,butwithadifferentjury,
thejuryawardedasimilarlevelofcompensatorydamages,butnopunitivedamagesatall.
ThejuryfoundthatBMW’sbehaviordidnotrisetothelevelofreprehensibilitydeserving
ofpunitivedamages.2
*HillelJ.Bavli,TheLogicofComparable-CaseGuidanceintheDeterminationofAwardsforPainandSufferingandPunitiveDamages,U.Cin.L.Rev.(forthcoming,2017).TheauthorthanksDonaldRubin,DavidRosenberg,JosephBlitzstein,KennethShepsle,andYangChenfortheirhelpfulcomments,andJohnKennethFelterandtheUniversityofCincinnatiLawReviewEditorialBoardfortheirhelpfuledits.
1 The Alabama Supreme Court reduced the award to $2million, and the United States Supreme Courtultimatelyreversed,holdingthateven$2millioninpunitivedamageswasgrosslyexcessive.SeeBMWofNorthAmerica,Inc.v.Gore,517U.S.559(1996).
2SeeGeorgeL.Priest,IntroductiontoCassR.Sunsteinetal.,PUNITIVEDAMAGES:HOWJURIESDECIDE2-3(2002).
69
TheawardsintheBMWcase,likeothers—suchasamedicalmalpracticecase
resultinginapainandsufferingawardof$100million3oradeceptive-cigarette-marketing
caseresultinginapunitivedamagesawardof$28billion4—representsastarkdeviation
fromJusticeHolmes’scharacterizationofthelawasa“systematizedprediction.”5AsJudge
Niemeyercommentedregardingthe$100millionawardinEvans,“Becausethejurywas
givennorulenoranyrationalcriteriatoapplyinsettingtheamountofsuchanaward,but
toldsimplytodowhatitthoughtbest,thejuryrespondedwithaperceived‘measurement’
ofthepain,whichessentiallyamountedtoanemotionalresponse.”6Thejuryawardin
Evans—anawardtentimestheamountrequestedbytheplaintiff’sattorney,andonethat
thetrialjudgeultimatelyreducedto$3.5million—suggests,atleast,thatsuchawardsare
unpredictable.7RegardingtheawardinBullock,JudgeNiemeyercommentedthat“only
emotion,notaruleoflaw,couldjustifyimposinganawardof$28billion.Toconfirmthis,
3SeeEvansv.St.Mary’sHosp.ofBrooklyn,1A.D.3d314(N.Y.App.Div.2003).
4SeeBullockv.PhilipMorrisInc.,No.BC249171,2002WL31833905(Cal.App.Dep’tSuper.Ct.Dec.18,2002).
5OliverWendellHolmes,ThePathoftheLaw,10HARV.L.REV.457,458(1897).JusticeHolmesobservedthat“[p]eoplewanttoknowunderwhatcircumstancesandhowfartheywillruntheriskofcomingagainstwhatissomuchstrongerthanthemselves,andhenceitbecomesabusinesstofindoutwhenthisdangeristobefeared.Theobjectofourstudy,then,isprediction,thepredictionoftheincidenceofthepublicforcethrough the instrumentality of the courts.” Id. at 457. See also Paul v. Niemeyer, Awards for Pain andSuffering:TheIrrationalCenterpieceofourTortSystem,90VA.L.REV.1401,1402-04(2004).
6Niemeyer,supranote5,at1403.
7Id.at1403-04.
70
oneneedonlyconsiderthe‘mind’ofalegislativebodydevelopingaprospectiveruleoflaw
topunishsimilarconduct.”8
Indeed,numerousempiricalstudieshaveconfirmedsubstantialanecdotalevidence
thatawardsforpainandsufferingandpunitivedamagesarehighlyunpredictable.9
Commentatorshaveproposednumerousmethodstoaddressunpredictability,
includingvariousformsofawardschedulesthatbindorguideajuryinitsaward
determinationinlightofitsfindingsregardingcertainfacts,suchastheseverityofa
plaintiff’sinjuries.10Thus,“[s]cheduleswithcategoriesbasedoninjuryseveritytypically
providethemethodofclassification,andpriorawardsforinjurieswithineachcategory
providearangeofdamagesamounts.”11Thatis,“[a]lthoughreformsofthistypedifferin
8Id.at1409-10(notingthatthe“Californialegislaturehasfixedthemaximumfineforfalseadvertisingat$2500,”andthat“Congresshasfixedthemaximumfineforcorporations’violationsoffederaloffensesat$500,000ortwicethedefendant’sgainorthevictim’sloss”).
9SeeShariSeidmanDiamondetal.,JurorJudgmentsAboutLiabilityandDamages:SourcesofVariabilityandWaystoIncreaseConsistency,48DEPAULL.REV.301,317(1998)(concludingthatthereis“considerablevariationinbothjurorandjuryawards,”andthat“[a]substantialportionofthatvariationisnotpredictablefrommeasuresofeitherbackgroundorattitudinalindividualdifferencesacrossjurors”);RandallR.Bovbjergetal.,ValuingLifeandLimbinTort:Scheduling”PainandSuffering,”83NW.U.L.REV.908,919-24(1989)(concludingthat“[a]lthoughthemedian,andevenmean,awardsinagivencategorymaybeconsideredrelativelyreasonable,theseeminglyuncontrolledvariabilityofawardsiscauseforconcern—similartoanxietyaboutdrowninginapoolaveragingonlytwofeetindepth”);OscarG.Chase,HelpingJurorsDeterminePainandSufferingAwards,23HOFSTRAL.REV.763,768-69(1995)(citingstudies);DavidW.Leebron,FinalMoments:DamagesForPainandSufferingPriortoDeath,64N.Y.U.L.REV.256,259(1989)(concludingthat“tortawardsforeventhisrelativelysimplearea[ofdamagesforpainandsufferingpriortodeath]varysignificantlyandthatneitherthespecificfactsofthecasenordifferingtheoreticalviewsofthefunctionsoftheawardscanexplainsuchvariation”).SeealsoRichardAbel,GeneralDamagesAreIncoherent,Incalculable,Incommensurable,andInegalitarian(butOtherwiseAGreatIdea),55DEPAULL.REV.253,291-303(2006).ButseeYun-chienChangetal.,PainandSufferingDamagesinPersonalInjuryCases:AnEmpiricalStudy,UNIV.OFCHICAGOCOASE-SANDORINST.FORLAW&ECON.RESEARCHPAPERNO.749(April12,2016),http://papers.ssrn.com/abstract=2741180(concludingthat“painandsufferingdamagesinTaiwanaretoalargeextentstatisticallyandlegallypredictable”).
10SeeinfraSection3.
11MarkGeistfeld,PlacingAPriceonPainandSuffering:AMethodforHelpingJuriesDetermineTortDamagesforNonmonetaryInjuries,83CAL.L.REV.773,791(1995).
71
theirdetails,eachproceedsfromthepremisethatpriorpain-and-sufferingawardsfor
similarcasesprovidetheappropriatebasisforcomputingthepresentaward.”12Ultimately,
“[t]hejuryorreviewingcourtdetermineswheretheplaintiff’sinjuryfallsontheschedule,
andthescheduleprovidesarangeorspecifiedamountthatcanbebindingornonbinding
onjuriesorcourts.”13
Totheextentthatthesemethodspredeterminetheawardorrangeofawards,and
totheextentthattheybindthejuryratherthanguideit,theyhavebeencriticizedas
“eviscerat[ing]thevariouscontributionsthatjuriesmaketotheciviljusticesystem,”andas
being“inconsistentwiththebasictortprinciplethateachvictimisentitledtoanaward
tailoredtohisorhercircumstances,setbyalayjury.”14
Asimilarrecommendation,proposedpreviouslyinvariousforms,involves
“comparabilityanalysis.”Usingthisapproach,thecourt(perhapsbywayofanadversarial
processinvolvingthelitigationparties,andeventhetrieroffact)wouldfirstidentifya
universeofcomparablecases.Itwouldthenprovidethetrieroffactwithcertain
informationregardingtheawardsinthesecasesinthecontextofajuryinstructionoras
experttestimony,anditwouldinstructthetrieroffacttoarriveatadamages
determinationinlightoftheevidenceintroducedinthecase,andusingthecomparable-
caseinformation(or“prior-awardinformation”)asguidance.15Suchmethodsarebased,in
12Id.
13Id.
14DavidA.Logan,Juries,Judges,andthePoliticsofTortReform,83U.CIN.L.REV.903,942-43(2015).
15See infraSection3. Notethatthere issubstantialoverlapbetweensuchmethodsandthose involvingscheduling—particularlytotheextentthatschedulingmethodologiesinvolveprovidingafact-finderwithscenariosandassociatedawardvalues,basedoncomparablecases,asguidanceindeterminingdamages.
72
part,onempiricalstudiesconfirmingthattheyareeffectiveincontrollingoutlyingawards
andreducingawardvariabilitygenerally,evenusingpriorawardstoguide,ratherthan
bind,thetrieroffact.16
Forpurposesofclarity—becausetheterms“damageschedule”and“comparability
analysis”havebeenusedintheliteraturetomeanvariousthingsinvariouscontexts—Iwill
usetheterm“comparable-caseguidance”(CCG)torefertoschedulingorcomparability-
analysismethodsthatfulfillthreefundamentalrequirements:1)informationusedas
guidancemustbederivedfromprior“comparable”cases(asopposedto,e.g.,damage
schedulespredeterminedarbitrarilybyalegislativebody);2)comparable-case
informationmustbeconsideredbythetrieroffactinparticular(asopposedto,e.g.,a
reviewingcourt);and3)comparable-caseinformationmustbeusedasguidanceonly(as
opposedto,e.g.,imposingarangeoramountthatisbindingonthetrieroffact).17
WhileCCGmethodsallowforacase-by-caseanalysisthatremainsinthediscretion
ofthetrieroffact,theuseofpriorawardsitselfhasbeenattackedbasedonthree
fundamentalobjections.First,“[i]fthesystemhasbeenprovidingoverlyarbitrarypain-
and-sufferingawards,andifwehavenomethodfordeterminingtheappropriateawardin
thefirstinstance,whyshouldwemakepriorawardsthecornerstoneoffutureawards,”
since“[b]ydoingso,wemayensurethatlikecasesaretreatedalikeinthatallinvolve
SeealsoMichaelJ.Saksetal.,ReducingVariabilityinCivilJuryAwards,21LAWANDHUMANBEHAVIOR243,246(1997);Bovbjergetal.,supranote9,at953.
16See,e.g.,Saksetal.,supranote15,at249-55.
17Notethattheanalysishereinmayapplytoschedulingandcomparabilityanalysismorebroadly;however,IfocusonCCGmethodsinparticular.
73
inappropriatedamagesawards.”18Second,suchmethods“failtoaddressthefundamental
issueofhowoneshouldinitiallyassessthevalueofpain-and-sufferingdamages”orarrive
atanappropriatepunitivedamagesaward.19Third,thevalidityofsuchmethodsrelies
heavilyonthepresumptionthata“correct”setofcaseshasbeenidentified—thattheprior
casesidentifiedareindeedmaterially“comparable”tothecaseathand.20
Theseobjectionsboildowntoafundamentalconcern:ifourproblemisthe
unpredictabilityofawardscausedbyatrieroffact’sinabilitytoassessobjectivelythe
appropriatevalueofawardsforpainandsufferingorpunitivedamages,howisitbeneficial
toprovideatrieroffactwithinformationregardingdamagesawardedinpriorcasesthat
areseparateanddistinctfromthepresentcaseandthatpresumablysufferfromthesame
18Geistfeld,supranote11,at792(commentingthat“[t]hisrelianceuponpastawards...representsthemostproblematicaspectofthesereformproposals”).SeePeterH.Schuck,ScheduledDamagesandInsuranceContractsforFutureServices:ACommentonBlumstein,Bovbjerg,andSloan,8YALEJ.ONREG.213,218(1991)(“byusingearlierawardsasthefoundationfortheirnewsystemofdamagesscheduling,theyimpoundandthencompoundwhattheythemselvescharacterizeasthedistortionsofthepast,therebyprojectingthosedistortionsintothefuture”);seealsoRobertL.Rabin,ThePervasiveRoleofUncertaintyinTortLaw:RightsandRemedies,60DEPAULL.REV.431,448-49(2011)(“SchedulingproposalsofthiskindhavebeencriticizedbytortsscholarssuchasMarkGeistfeld,whopointedouttheseemingparadoxinrejectingunstructuredjurydecisionmakinginfavorofascheduledapproach,whichfromahorizontalequityperspectivetakesarbitrarypriorawardsasthecornerstoneforfutureawards,andfromaverticalequityperspectivetakestheorderingofmagnitudeinpastjuryawardsasanappropriatekeyforhierarchicalsortinginthedesignatedseverity-categoriesforfutureawards”).
19RonenAvraham,PuttingAPriceonPain-and-SufferingDamages:ACritiqueoftheCurrentApproachesandAPreliminaryProposalforChange,100NW.U.L.REV.87,104(2006)(discussingpain-and-sufferingawardsinparticular,andcitingW.KipViscusi,PainandSuffering:DamagesinSearchofASounderRationale,1MICH.L.&POL’YREV.141,168(1996)(“Thekeyissuetoberesolve[d]forpainandsufferingschedulesandscalesisthatestablishingsucharbitrarybenchmarksdoesnotresolvethemorefundamentalissueofhowoneshouldinitiallyassessthevalueofpainandsufferingdamages”)).
20SeeLogan,supranote14,at943-44(“While[anapproachallowingthefact-findertoconsiderarangeofpossibleawardsforguidance]wouldimprovepredictability,suchanapproachwouldonlybeasgoodasthequalityofthemethodologyforselectingwhichcaseswerefactuallysimilarenoughtobeincludedintherange”).
74
arbitrarinessthatwewishtoaddressinthepresentcase?Seemingly,thiswouldonly
compoundtheproblem.
Myaiminthisarticleistoaddresstheseobjectionsbyexplaininginsimplebut
formaltermshow,notwithstandingtheforegoingobjections,CCGmethodsreduce
unpredictabilityandimproveawardsforpainandsufferingandpunitivedamages
generallybyallowingforthesharingofrelevantinformationacrosscases.
Section2discussestheimportanceofreducingthevariabilityofawardsforpainand
sufferingandpunitivedamages.Section3providesbackgroundregardingcurrentmethods
andproposalsforreducingawardvariability.Section4explainshowCCGmethodsreduce
unpredictabilityandimproveawardsforpainandsufferingandpunitivedamages
generally.Section5discussesanumberofconsiderationsforidentifyingauniverseofprior
casesandfordistillinginformationfromsuchcasesforconsiderationbythetrieroffact.
Section6providesadditionallegalcontextforCCGmethodsandconcludes.
2. TheImportanceofReducingtheVariabilityofAwardsforPainand
SufferingandPunitiveDamages
TheSupremeCourthasrepeatedlyemphasizedtheimportanceofmaintainingfair
andconsistentawardsforpainandsufferingandpunitivedamages.Inarecentcase,for
example,theCourtstated:
Therealproblem, itseems, is thestarkunpredictabilityofpunitiveawards.Courtsof lawareconcernedwithfairnessasconsistency,andevidencethatthemedianratioofpunitivetocompensatoryawardsfallswithinareasonablezone,orthatpunitiveawardsareinfrequent,failstotelluswhetherthespread
75
between high and low individual awards is acceptable. The available datasuggestitisnot.21TheSupremeCourtcontinuedbydiscussingthe“inherentuncertaintyofthetrial
process”andtheresultinginconsistencyamongawardsincaseswithsimilarfacts.22In
examiningunpredictabilityasamatterofpolicy,ratherthanofconstitutional
significance,23theCourtemphasizedthattheunpredictabilityofhighpunitivedamage
awardsis“intensionwiththefunctionoftheawardsaspunitive.”24Itcommented:
Thus,apenaltyshouldbereasonablypredictableinitsseverity,sothatevenJusticeHolmes’s“badman”canlookaheadwithsomeabilitytoknowwhatthestakesareinchoosingonecourseofactionoranother.SeeThePathoftheLaw,10Harv.L.Rev.457,459(1897).Andwhenthebadman’scounterpartsturnup fromtimeto time, thepenaltyschemethey faceought to threaten themwithafairprobabilityofsufferinginlikedegreewhentheywreaklikedamage.Cf.Koonv.UnitedStates,518U.S.81,113(1996)(notingtheneed“toreduceunjustified disparities” in criminal sentencing “and so reach toward theevenhandedness and neutrality that are the distinguishing marks of anyprincipledsystemofjustice”).Thecommonsenseofjusticewouldsurelybarpenaltiesthatreasonablepeoplewouldthinkexcessivefortheharmcausedinthecircumstances.25
21ExxonShippingCo.v.Baker,554U.S.471,499(2008)(citingTheodoreEisenbergetal.,Juries,Judges,andPunitiveDamages:EmpiricalAnalysesUsingtheCivilJusticeSurveyofStateCourts1992,1996,and2001Data,3J.OFEMPIRICALLEGALSTUD.263,267(2006);ThomasH.Cohen,PunitiveDamageAwardsinLargeCounties,2001,U.S.DEPT.OFJUSTICE5(Mar.2005),http://www.bjs.gov/content/pub/pdf/pdalc01.pdf;BrianJ.Ostrometal.,AStepAboveAnecdote:AProfileoftheCivilJuryinthe1990s,79JUDICATURE233,240(1996);ErikK.Molleretal.,PunitiveDamagesinFinancialInjuryJuryVerdicts,28J.LEGALSTUD.283,333(1999)).
22Id.,554U.S.at500-01(quotingBMWofNorthAmerica,Inc.v.Gore,646So.2d619,626(1994)).
23TheSupremeCourthighlightedthat“theCourt’sresponsetooutlierpunitive-damagesawardshasthusfarbeenconfinedbyclaimsattheconstitutionallevel,andourcaseshaveannounceddueprocessstandardsthateveryawardmustpass.”Id.at501.InBaker,however,theCourtexaminedajuryawardforpunitivedamages“forconformitywithmaritimelaw,ratherthantheouterlimitallowedbydueprocess.”Id.at501-02.Inacting“inthepositionofacommonlawcourtoflastreview,”id.at507,itconsideredpunitivedamagesnotwithrespectto“theirintersectionwiththeConstitution,”butratherinrelationtothe“desirabilityofregulatingthemasacommonlawremedy.”Id.at502.
24Id.at502(emphasisadded).
25Id.at502-03.
76
TheSupremeCourtthusemphasizedthepointthatpredictability,consistency,and
fairnessarefundamentaltothedeterrenceobjectivesunderlyingpunitivedamages.This
sentimentandothersassociatedwiththeharmsofunpredictabilityhavebeenechoed
repeatedlybylowercourtsandscholars.
Forexample,inthecaseofPaynev.Jones,theSecondCircuitexplainedthepurposes
underlyingthedeviceofremittiturbyemphasizingtheharmfuleffectsofvariabilityand
outlyingawards,includingthoseassociatedwithover-deterrence:
Apart from impairing the fairness, predictability andproportionality of thelegalsystem,judgmentsawardingunreasonableamountsasdamagesimposeharmful, burdensome costs on society. As an initial matter, an excessiveverdictthatisallowedtostandestablishesaprecedentforexcessiveawardsinlatercases.Thepublicitythataccompanieshugepunitivedamagesawards,see,e.g.,HenryWeinstein,PhilipMorrisOrderedtoPay$28BilliontoSmoker,L.A.Times,Oct.5,2002,willencouragefuturejurorstoimposesimilarlylargeamounts. Unchecked awards levied against significant industries can causeseriousharmto thenationaleconomy.Productivecompaniescanbe forcedintobankruptcyoroutofbusiness.Municipalitiescanbedrainedofessentialpublicresources.Thethreatofexcessivedamages,furthermore,drivesupthecost of insurance premiums, deters both individuals and enterprises fromundertaking socially desirable activities and risks, and encouragesoverspendingon“sociallyexcessiveprecautions”that“cost[]morethanthereductionofharmproducedby[them].”A.MitchellPolinsky&StevenShavell,PunitiveDamages:AnEconomicAnalysis,111Harv.L.Rev.869,879(1998).Thepricesofgoodsandserviceswillrise,andinnovationwillbeinhibited.Seeid.at873.26
Courtshavesimilarlyemphasizedtheneedto“minimizethearbitraryvariancein
awardsboundtoresultfrom[the]throw-up-the-handsapproach”thatcourtsregularlyuse
indeterminingawardsforpainandsuffering.27Courtsandscholarshaverecognizedthe
26Paynev.Jones,711F.3d85,94(2dCir.2013).
27Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001).
77
needtoaddressthis“standardless,unguidedexerciseofdiscretionbythetrieroffact,
reviewable...pursuanttonostandardtoguidethereviewingcourteither.”28
InGeressyv.DigitalEquip.Corp.,JudgeWeinsteinexplainedthecourt’sdecisionto
considerprior-awardinformation.Hediscussedconcernbythecourtsandlegislaturefor
the“virtuallyunbridleddiscretion”ofjuriesinawardingdamagesforpainandsuffering,
forwhichthereis“currentlynomeaningfulwaytomeasuresuchnon-quantifiablelosses
monetarily.”29AsProfessorOscarChaseexplained:
Variability is aproblemprimarilybecause itundermines the legal system’sclaimthatlikecaseswillbetreatedalike;thepromiseofequaljusticeunderlawisanimportantjustificationforourlegalsystem.Variabilityisalsoclaimedtocreateinstrumentaldefects;thatis,itmakesithardertosettlecases,thusadding unnecessary transaction costs to the tort system, and delayingpayment to needful plaintiffs. Unpredictability also leads to inefficienciesbecauseofover-orunder-precautionsbyaffectedindustriesandinsurers.30
Thus,whetherforpurposesoffairness,deterrence,oranotherobjective,courts
recognizetheimportanceofgeneratingconsistentandpredictabledamageawards.Indeed,
reducingvariabilityisfundamentaltoachievingreliablelegaloutcomes.InSection4,I
considervariabilityinthecontextoferrorgenerally,anddiscussinmoredetailwhatis
meantby“reliablelegaloutcomes.”First,however,Idescribecurrentmethodsand
proposalsforaddressingawardvariability.
28Id.
29Geressyv.DigitalEquip.Corp.,980F.Supp.640,656(E.D.N.Y.1997)(quotingLeslieA.Rubin,ConfrontingaNewObstacletoReproductiveChoice:EncouragingtheDevelopmentofRU-486ThroughReformofProductsLiabilityLaw,18N.Y.U.REV.L.&SOC.CHANGE131,146(1990-91)).
30Chase,supranote9,at769.
78
3. CurrentMethodsandProposalsforAddressingAwardVariability
AdditurandRemittitur
Courtsusetheproceduraldevicesofadditurandremittiturtoincreaseordecrease
anawardfoundtobeinsufficientorexcessive.Forexample,adefendantmayarguefora
newtrialbasedontheexcessivenessofthejury’saward.Ifthejudgeagrees,hemayoffer
theplaintifftoreducetheaward(remittitur)bysomeamountratherthanproceedingwith
anewtrial.31Appellatecourtsmayalsomodifyawardsandaddresschallengestoadditur
andremittitur.32
Althoughthedevicesofadditurandremittiturcan,intheory,addressthehighlevels
ofvariabilityassociatedwithawardsforpainandsufferingandpunitivedamages,in
practicetheycannot.First,additurandremittiturareprimarilyusedtoaddressexcessive
awards,andareinfrequentlyusedtoadjustinadequateawards.33Second,theseprocedures
aregenerallyreservedforonlythemostextremecases—theyareusedtoaddressextreme
outliersthataredeemedincorrect,ratherthanaddressvariabilityingeneral.34Third,
courtslackconsistentandprincipledproceduresforarrivingatbetteraward
determinationsthanjuries.AsJudgePosneropinedinJutzi-Johnsonv.UnitedStates,“[most
31 David Baldus et al., Improving Judicial Oversight of Jury Damages Assessments: A Proposal for theComparativeAdditur/RemittiturReviewofAwardsforNonpecuniaryHarmsandPunitiveDamages,80IOWAL.REV.1109,1118-20(1995).
32Id.Bothstateandfederalcourtsusetheadditurandremittiturprocedures;buttheSupremeCourthasdistinguishedadditur fromremittiturandheld that the formerprocedure isviolativeof thedefendant’sSeventhAmendmentrighttoatrialbyjury.SeeDimickv.Schiedt,293U.S.474(1934).
33SeeBaldusetal.,supranote31,at1119-20.
34Seeid.at1118-20.
79
courts]treatthedeterminationofhowmuchdamagesforpainandsufferingtoawardasa
standardless,unguidedexerciseofdiscretionbythetrieroffact,reviewableforabuseof
discretionpursuanttonostandardtoguidethereviewingcourteither.”35Further,courts
employthesedevicesinfrequently;36andwidespreadreplacementofjuryawardswith
judicialdeterminationswouldbeproblematicwithrespecttotheSeventhAmendmentand
fundamentalprinciplesoftortlaw.
DamageCaps.Similarly,damagecaps,whichplaceupperlimitsondamageawards
orcertaintypesofdamageawards,arewidelyrecognizedasaparticularlypoormethodfor
addressingvariability.37Theygiverisetoarangeofproblemsinherentincappingdamages
35Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001).
36 See Baldus et al., supranote 31, at 1119-21 (citingMichael G. Shanley&Mark A. Peterson,PosttrialAdjustments to Jury Awards vii-viii, 43-47, RAND: THE INST. FOR CIVIL JUSTICE (1987)http://www.rand.org/content/dam/rand/pubs/reports/2007/R3511.pdf,andothers).Baldusetal.notethat“[o]nthebasisofpost-trialinformationinthe8801982-84CaliforniaandCookCounty,Illinoiscasesreportedin[theShanleyandPetersonstudy],weestimatethatincasesinvolvingadamagesaward,therewasaremittiturornewtrial6%ofthetimeandanaddituroranegotiatedincreaseintheawardin2-3%ofthecases.”SeealsoJosephSanders,WhyDoProposalsDesignedtoControlVariabilityinGeneralDamages(Generally)FallonDeafEars?(andWhyThisIsTooBad),55DEPAULL.REV.489,503(2006).
37Damagecapshaveservedastheprimarytooloftortreformaimingtoaddressvariability.Legislationforcapsboomedduringheightenedcallsfortortreforminthe1970sand1980s,andby1987,twenty-threestateshadinstitutedcapsrangingfrom$150,000to$1,000,000.Sanders,supranote36,at510.SeealsoStephenD.Sugarman,AComparativeLawLookatPainandSufferingAwards,55DEPAULL.REV.399,399-400(2006).Sincethen,numerousotherstateshaveadoptedcapsinvariouscontextsaswell.Sanders,supranote36,at510.Statutorycapsmaybeappliedtospecifictypesofdamages,suchaspunitivedamagesorgeneraldamages,ordamageawardsgenerally.SeeBaldusetal.,supranote31,at1121-23.Theymaybeapplied in particular contexts, such asmedicalmalpractice. See generallyKathryn Zeiler,Turning fromDamageCapstoInformationDisclosure:AnAlternativetoTortReform,5YALEJ.HEALTHPOL’Y,L.ÐICS385(2005).Andtheyappearinavarietyofforms.Forexample,juriescanbeinformedofdamagecapsexplicitly,oracapcanbeappliedbythecourtonlyafterajuryhasexceededit.Ingeneral,juriesarenotinformedofcaps;but,regardless,jurorsmaybeawareofsuchmeasures.SeeSaksetal.,supranote15,at245.Undersomeproposals,ajudgemaybepermittedtoreduceawardsbelowthequantityprovidedbythelegislation;inothers,a judgemaybepermittedonly toreduceanaward to theestablishedquantity.SeeColleenP.Murphy,StatutoryCapsandJudicialReviewofDamages,39AKRONL.REV.1001,1002-08(2006).
80
(orcertaintypesofdamages)outright,independentofthecircumstancesofthecaseor
harmsufferedbytheplaintiff.
First,capsaddressonlythemostextremecases,andonlyexcessiveawards.Second,
capsarelikelytoplayaroleprimarilyincasesinwhichtheharmisverysevere.If,for
example,thereisacapof$1million,thecapmaynotaffectanindividualwhosuffereda
brokennose,butwouldgreatlyaffectanindividualwhosufferedparalysis.Thecapis
unlikelytoaddressvariabilityintheformercase,whilepossiblycausinganinappropriately
lowawardinthelatter.38Thus,asidefrombiasingtheaward,capsdistortincentivesto
litigatetortclaimsbasedonsevereharm.Further,capscancausesuboptimalrisk-takingby
dilutingthedeterrenceeffectofpunitivedamagesandtortlawgenerally.39Third,anumber
ofstudieshaveconcludedthatcapsmayinfactexacerbatethevariabilityproblemrather
thanaddressit.Inparticular,jurorswhoareawareofacapmayanchortoit,andtheir
awardsmaygravitatetoit.“Thus,thosewiththemostsevereinjuriesandlosseswillbe
unfairlydeprivedofcompensationbycaps.Inaddition,byservingasapsychological
anchor,capsappearlikelytofurtherexaggeratetheerrorofovercompensatingthosewith
smallerlosses.”40
38SeeBaldusetal.,supranote31,at1121-23.
39SeeSanders,supranote36,at509-11.Constitutionalityissuesmayariseaswell.Opponentsofcapshaveargued,forexample,thatcapsareviolativeofaplaintiff’srighttotrialbyjury.SeeZeiler,supranote37,at387.
40Saksetal.,supranote15,at245.SeealsoVerlinB.Hinsz&KristinE.Indahl,AssimilationtoAnchorsforDamageAwardsinaMockCivilTrial,25J.OFAPPLIEDSOC.PSYCHOLOGY991(1995).
81
But,notwithstandingtheforegoingproblems,damagecapsareused,due,inpart,to
theiradministrativeconvenienceandtheirabilitytocontrolinsurancerates.41
Comparable-CaseInformation.Finally,anumberofcourtsandcommentators
haveproposedmethodsinvolvingtheuseofinformationregardingawardsinprior
“comparable”cases.Suchproposalshaveappearedinvariousforms.Onesetofapproaches
buildsoncourts’regularuseofcomparabilityreview,wherebytrialandappellatecourts
considerawardsincomparablecasesintheirreviewofatrieroffact’sawardfor
excessiveness.42Theseproposalsattempttodevelopamorestructuredframeworkforthe
court’scomparativeanalysis—forexample,institutingamethodbywhichacourtidentifies
auniverseofcomparableclaims;examineswhetherthecurrentaward“deviatesmaterially
fromwhatwouldbereasonablecompensation”(touselanguagefromaNewYorkstatute
uponwhichsuchproposalsseemtobuild);43and,ifso,determinesasuitableadjustmentof
thejuryaward.44
Thesereview-basedmethodshavetheadvantageofinvolvingonlymodest
modificationstocurrentwell-acceptedmethods,buttheyarenotideal.Specifically,they
incorporatecomparable-caseinformationonreviewratherthanintheawarddirectly.As
such,theyonlyfocusonoutlyingawardsratherthanonvariabilityingeneral.Moreover,
41SeeSanders,supranote36,at511.
42SeeBaldusetal.,supranote31,at1134.
43N.Y.C.P.L.R.5501(c)(McKinney1995).
44SeeBaldusetal.,supranote31,at1134.SeealsoSanders,supranote36,at503.
82
regularuseofsuchmethodsarguablyleadstoconstitutionalityandtortissuesassociated
withthereplacementofajury’sdiscretionwiththatofthejudge.45
AsindicatedintheIntroduction,anothersetofproposalsusesvarioustypesof
schedulestobindorguidethetrieroffactinitsdeterminationofcertaintypesofdamage
awards.46Theseproposals,totheextenttheyinvolvebindingatrieroffactto
predeterminedvaluesorrangesofvalues,havebeencriticizedasimpingingonthetrierof
fact’sdiscretion,andas“inconsistentwiththebasictortprinciplethateachvictimis
entitledtoanawardtailoredtohisorhercircumstances,setbyalayjury.”47Totheextent
thatsuchmethodsbindratherthanguidethetrieroffact,andtotheextentthatthey
involveawardvaluesthatarepredetermined,forexample,byalegislativebodyinadvance
ofthecase,suchmethodsarearguablyproblematic.
Finally,anumberofproposals—overlappingwiththecategoryaboveregarding
schedules—involvecomparabilityanalysis,wherebythecourt(perhapsbywayofan
adversarialprocessinvolvingthelitigationparties,andeventhetrieroffact)identifiesa
setofmaterially“comparable”cases,providesthetrieroffactwithcertaininformation
regardingtheawardsinthesecasesinthecontextofajuryinstructionorpresentedas
45SeeColleenP.Murphy,JudicialAssessmentofLegalRemedies,94NW.U.L.REV.153,192(1999);J.PatrickElsevier,Out-of-Line:FederalCourtsUsingComparabilitytoReviewDamageAwards,33GA.L.REV.243,258-59 (1998) (“Comparability analysis [on review] requires a court to engage in several subjective,factintensiveinquiries...Yet,byassertingthatcomparabilityprovidesanobjectiveframeworktoreviewcompensatorydamageawards,courtsareabletosubstitutetheirownassessmentofwhattheappropriatedamageawardshouldbe,whileskirtingtheSeventhAmendment’sproscriptionagainstreexaminationofissuesoffact”).
46See,e.g.,Bovbjergetal.,supranote9,at945.
47Logan,supranote14,at943.
83
experttestimony,andinstructsthetrieroffacttodetermineanappropriatedamages
awardinlightoftheevidenceintroducedinthecase,andusingthecomparable-case
informationasguidance.48
AssuggestedintheIntroduction,suchmethods—andCCGmethodsinparticular—
avoidmanyoftheproblemscausedbyothermethods,suchasdamagecapsandbindingor
predeterminedschedules.Thesemethodsallowforaflexiblecase-by-caseanalysisinthe
discretionofthetrieroffact,whilestillprovidingsubstantialguidance.Nevertheless,such
methodshavebeenattackedonthegroundsthat,insteadofaddressingthefundamental
issueofassessingthevalueofpain-and-sufferingdamagesoranappropriatepunitive
damagesaward,theymaycompoundtheunpredictabilityofdamageawardsbyproviding
thetrieroffactwithinformationregardingdamagesawardedinseparateanddistinctprior
casesthatpresumablysufferfromthesamearbitrarinessthatthecourtaimstoaddressin
thepresentcase.49Inthefollowingsections,Iaddresstheseobjections.
4. TheLogicofCCG
Inthissection,Iexplainwhy,notwithstandingtheobjectionsdelineatedabove,CCG
methodsreduceunpredictabilityandimprovethereliabilityofawardsforpainand
sufferingandpunitivedamagesgenerally.Ibeginbydiscussingwhatismeantby
48See,e.g.,Chase,supranote9,at777-90(proposingthatcourtsinformjurorsof“therangeofawardsmadebyotherjuriesinthesamestateforsuchdamagesduringacontemporaneoustimeperiod,”tobeprovidedas non-binding guidance in the court’s charge to the jury in the form of a “chart constructed to allowcomparison with roughly similar cases in which plaintiffs’ verdicts were recovered.” Id. at 777.). SeegenerallyBaldusetal.,supranote31,at1123-24;Saksetal.,supranote15,at246;Sanders,supranote36,at 506-7; JACOB A. STEIN, STEIN ON PERSONAL INJURY DAMAGES TREATISE §8:32 (3d ed. 2015) (discussingAmericanBarAssoc.,ReportoftheActionCommissiontoImprovetheTortLiabilitySystem10-15(1987));Jutzi-Johnsonv.UnitedStates,263F.3d753,758-61(7thCir.2001).
49SeeGeistfeld,supranote11,at792;Avraham,supranote19,at104;Logan,supranote14,at943-44.
84
“reliability.”IthenintroducetheroleofCCGinreducingvariabilityanderrorin,andthus
improvingthereliabilityof,legaloutcomes.
4.1 BiasandVariance:TheElementsofError
Section2makesclearthatcontrollingthevariabilityofawardsforpainand
sufferingandpunitivedamagesisimportant.Butreducingvariabilitydoesnotnecessarily
meanimprovingtheaward.Forexample,itislikelyunwisetoencouragejurorstoanchor
toanarbitraryvalue,notwithstandingassociatedvariabilitybenefits.Infact,variability
couldbezeroifthecourtweretodictateanawardwithoutregardtotheparticularsofthe
case.
Courtsandscholarsarecorrecttobeconcernedaboutthehighvariability
associatedwithawardsforpainandsufferingandpunitivedamages.Butgoodpolicy
requiresstepstowardreducingsuchvariabilityonlyinsofarastheyimproveawards
generally.
Thus,forpurposesofconsideringtheconceptsof“error”and“accuracy”inthe
contextofdamageawards,assumethatthereissome“correct”awardthatcould,intheory,
bedeterminedasafunctionofperfectinformationregardingthestateoftheworld,
includingthefactsofthecaseandapplicablelawandnorms.50Ofcourse,weneitherhave
perfectinformationnorknowthecorrectaward.Instead,thecourtasksajurytoarriveat
anaward,whichwillserveasanestimateofthecorrectoutcome.
50SeeHillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation,14LAW,PROBABILITY&RISK67,74-78(2015). Wecansimilarlyconsiderarangeordistributionof “correct”awardsthatreflects,forexample,uncertaintyregardingthelaw.Id.at74n.24.
85
Moreconcretely,letusconsiderthecorrectawardinagivencase—say,forexample,
theBMWcasedescribedintheIntroduction—tobethemeanofthepopulationofpossible
awardsthatwouldemergefromadjudicatingthecaserepeatedlyundervariousconditions
(e.g.,beforedifferentjudgesandjuries,bydifferentattorneys,withdifferentpermutations
offacts,etc.).51Asingletrialthusgeneratesasamplefromthepopulationandanestimate
ofthecorrectaward.52Calltheactualawardan“estimate,”andtheprocedurethat
generatestheestimatean“estimator.”53Wecanthendefine“error”intermsofdistance,
and(equivalently)“accuracy”intermsofproximity,betweentheestimateandthecorrect
award.54
Idefinethereliabilityofalegalprocedureastheaccuracyoftheoutcome(here,the
award)thatwecanexpectbyfollowingtheprocedure.Ifweexpectthatacertainlegal
51Id.(citingMichaelJ.Saks&PeterDavidBlanck,JusticeImproved:TheUnrecognizedBenefitsofAggregationand Sampling in the Trial of Mass Torts, 44 STAN. L. REV. 815, 833-34 (1992)). For simplicity, I ignore thepotential forbias. AsnotedinBavli, supranote47,“[i]tmaybemoreintuitivetoconsidertheconceptofa‘correct’verdict inthecontextofacriminaltrial.Consider, forexample,theO.J.Simpsonmurdertrial.Pollsshowthatover50%ofAmericansbelievethatthejuryarrivedatanincorrectverdict.Implicitinthepublic’sdisagreementwiththeverdictisanassumptionthatthereexistsa‘correct’outcome.Theframeworkdescribedaboveisintuitive:hadthejuryknownthetruefactsofthecase,andhadtherebeennoambiguityregardingtheapplicationofthelawtothefactsofthecase,thejurywouldhavearrivedatthecorrectconclusion.Butgivenambiguityregardingeitherthefactsofacaseorthestateofthelaw,itisunclearwhetheracriminaldefendantinfactsatisfiedtheelementsofthecrimecharged;andthejurymustarriveataverdict—‘guilty’or‘notguilty’—which serves as an estimate of the correct outcome, ‘guilty’ or ‘not guilty.’” Id. at 74 n.29. Similarly, thedeterminationof a civil damagesaward (or,e.g., aprison sentence) canbeunderstoodas anestimateof acorrectoutcome.Arguablycourtsimplicitlyacknowledgethischaracterizationwhen,forexample,acourtfindsajuryawardtobeexcessiveorinadequate.Finally,theformulationofthecorrectawardasthemeanofthepopulationofpossibleawardsoverrepeatedadjudicationsisintendedtocapture,e.g.,thestateofthelawasunderstoodbyvariousjudgesacrosstherelevantsociety,andthenormsofthetimeandfactsofthecaseasunderstoodbyvariouscombinationsofjurorsintherelevantsociety.
52Seeid.at74-75;Saks&Blanck,supranote51,at833-34.
53Id.Theestimatorcanbeunderstoodasthelegalprocedure—includingtherulesgoverningthetrial,theroleofthejudge,thejurydeliberation,etc.—thatgeneratesthelegaloutcome,which,inourexample,isthejury’spunitivedamagesaward.
54Seeid.at74-78.
86
procedurewillproduceanaccurateaward,wesaythattheprocedure(or,forsimplicity,
theaward)is“reliable.”55
Instatisticstherearetwosourcesoferror:biasandvariance.Ifanestimatoris
“unbiased,”thenitwillgeneratethecorrectvalueonaverage.Ifitis“biased,”thenitwill
generatetheincorrectvalueonaverage,andthe“bias”reflectsthedistancebetweenthe
valuetheestimatorgeneratesonaverageandthecorrectvalue.Biasisthereforeasource
oferror.Notethatitispossiblethatanunbiasedestimatorwillnevergeneratethecorrect
value—tobeunbiasedisonlytogeneratethecorrectvalueinexpectation,oronaverage.
Additionally,althoughunbiasednessisgenerallyunderstoodasagoodcharacteristicforan
estimatortohave,itdoesnotindicatelackoferror,sincethevaluesgeneratedbythe
estimatorcanvarywildlyaroundthecorrectvalue.Forexample,ifthecorrectpunitive
damagesvalueintheBMWcaseaboveis$100,000,thenrepetitionsofan“unbiased”
adjudicationmaygenerateestimatevalues(i.e.,damageawards)of$0,$50,000,$150,000,
and$200,000,whichareindeedcenteredatthecorrectvalue,$100,000,buttheawardsare
highlydispersedaround$100,000.Wewould,forexample,preferthatrepeated
adjudicationsgeneratethevalues$90,000,$95,000,$105,000,and$110,000;oreven
better,$100,000,$100,000,$100,000,and$100,000.
Thus,thesecondsourceoferroris“variance,”whichisameasureofdispersion.In
particular,ifanestimatorentailsahighlevelofvariance,thenitwillgenerateestimates
thatarehighlydispersedarounditsmean,oraverage,value.Iftheestimatorentailsahigh
55Seegenerallyid.
87
levelofvariance,butisunbiased,thenitwillgenerateestimatesthatarehighlydispersed
aroundthecorrectvalue.Inthiscase,wesaythattheestimatoris“unbiased,”butthatit
lacks“precision.”Iftheestimatoris“precise”but“biased,”thenitgeneratesvaluesthatare
tightlycenteredaroundthewrongvalue—anundesirablecircumstance.Ifanestimatoris
“precise”and“unbiased,”thenitwillgenerateestimatesthatarecloseinproximitytothe
correctvalue,andwesaythatitis“accurate.”
Thus,intheBMWexampleabove,theawards$90,000,$95,000,$105,000,and
$110,000reflectgreaterprecisionthan$0,$50,000,$150,000,and$200,000.And,the
awards$100,000,$100,000,$100,000,and$100,000reflectevengreaterprecision.
Moreformally,letαbethe“correct”awardand𝛼arandomvariabledefinedbythe
actualaward.Let𝐸(𝛼)betheexpectationof𝛼.Inotherwords,𝛼willequal𝐸(𝛼)on
average;andifwerepeatthetrialmanytimesthentheaverageofthepunitivedamage
awardswillbeapproximately𝐸(𝛼).
Biasisdefinedasthedifferencebetweentheexpectationoftheestimator𝛼andthe
correctawardα(theobjectwearetryingtoestimate).Moreformally𝐵𝑖𝑎𝑠 = 𝐸 𝛼 − 𝛼,and
itissaidthattheestimator𝛼is“unbiased”if𝐸 𝛼 = 𝛼.
Additionally,let𝑉(𝛼)bethevarianceof𝛼,wherevarianceisdefinedinthestandard
way.Thatis,
𝑉 𝛼 = 𝐸 𝛼 − 𝐸 𝛼 ) =1𝑛 𝛼" − 𝐸 𝛼 )
+
"23
.
88
Thevarianceoftherealizedawardsisthustheaverageofthesquaredifferences
betweentheawardsandtheaverageoftheawards.Forexample,thevarianceof$0,
$50,000,$150,000,and$200,000is3^( $0 − $100,000 ) + $50,000 − $100,000 ) +
$150,000 − $100,000 ) + $200,000 − $100,000 )).Thestandarddeviationof𝛼isthe
squarerootofthevariance:𝑆𝐷 𝛼 = 𝑉(𝛼).
Nowletusformallydefineerrorintermsofbiasandvariance.Therearemanyways
tomeasureerror(justastherearemanywaystomeasure,forexample,dispersion).For
instance,wemightdefineerrorbytherawdifferencesbetweentheestimatesandthe
correctvalue.Butjustasitisinconvenientforscientiststodefinedispersionbycalculating
therawdifferencesbetweentheestimatesandthemeanoftheestimates,56similar
inconveniencesarisefromdefiningerrorintermsofrawdifferences.Itturnsoutthata
convenientandoftensuitablemeasureoferroristhewell-acceptedmeansquarederror
(MSE),definedas𝑀𝑆𝐸 𝛼 = 𝐸[ 𝛼 − 𝛼 )].Inwords,wefindtheexpectationofthesquare
differencebetweentheestimatorandthecorrectvalue.
Now,usingMSEasourmeasureoferror,itiseasytoshowthat:
𝑀𝑆𝐸 𝛼 = 𝐸[ 𝛼 − 𝛼 )] = 𝑉𝑎𝑟𝑖𝑎𝑛𝑐𝑒 + 𝐵𝑖𝑎𝑠)
Thatis,error(definedhereasMSE)canbeseparatedintotwoelements:biasand
variance.57
56Forexample,usingsuchdifferencesresultsinthe“canceling”ofpositiveandnegativevalues.
57SeeSHARONL.LOHR,SAMPLING:DESIGNANDANALYSIS,§2.2(2ded.2010),foramathematicalproof,andalengthierdiscussion,ofthebias-variancedecomposition.
89
4.2 ReducingVariabilityandErrorwithPrior-AwardInformation
Letusviewacivilcaseasanestimationproblemwithintheframeworkdescribed
above.Thatis,foreveryclaimletusassumethatthereisa“correct”damagesaward(or,in
particular,a“correct”awardforpainandsufferingorpunitivedamages)α,definedasthe
meanofthepopulationofawardsthatwouldresultfromrepeatedadjudications,as
describedabove(andthatwouldreflect,forexample,perfectinformationregardingthe
applicablelawandthefactsofthecase).58Asdiscussed,wecannotknowthecorrectaward
andmustthereforearriveatasuitableestimate𝛼oftheunknowncorrectaward.
Thus,letusassume(forsimplicityratherthannecessity)that,onaverage,the
estimatewillequalthecorrectaward,butthatitentailssomedegreeofvariabilityσ2
aroundthecorrectaward.Thatis,𝛼isdistributedwithmeanαandvarianceσ2.
Notationally,𝛼~(𝛼, 𝜎)).
Ourgoalistoarriveatadamagesestimatethatisclosetothecorrectaward—thatis
“accurate”inthesenseofminimizingerror,asdefinedaboveby𝑀𝑆𝐸 𝛼 = 𝐸[ 𝛼 − 𝛼 )].
Instatistics,andthesciencesgenerally,determiningagoodestimatorforan
unknownquantityisveryimportantandisthesubjectofmuchresearch.Letususean
analogytobetterunderstandtheproblemandpossiblesolutions.Considerastudyby
statisticiansBradleyEfronandCarlMorris,inwhichtheyrecordedbattingaveragedatafor
eachofeighteenmajorleaguebaseballplayersthroughhisfirstforty-fiveofficialatbatsof
58SeeBavli,supranote50,at74-78.Wecandefinethe“correct”awardusingothermeasuresofcentraltendency,suchasthemedian,dependingonhowwewanttocharacterizeit.Themean,forexample,ismoresensitivethanthemediantoextremeawards.Forsimplicity,ouranalysisinthisarticlefocusesonlyonthemean.
90
the1970season.59Supposeourgoalis(astheirgoalwas)toestimatethebattingaverages
thatwouldemergeforeachplayerduringtheremainderoftheseason,usingonlythedata
collected.Letusfocusononeplayer,RobertoClemente,whosebattingaverageforhisfirst
45atbatswas.400.60
Initially,itmightseemelementarythataplayer’sbattingaverageforthefirstforty-
fiveatbatswouldserveasthebestestimatorforhisbattingaveragefortheremainderof
theseason.Thus,ourestimateofClemente’sremainder-of-the-season(or“after-forty-five”)
battingaveragewouldbe.400.Butitcanbeshownmathematicallyandempiricallythat
thisisnotinfactthebestestimator.Inparticular,thisestimator—Clemente’sbatting
averageforhisfirstforty-fiveatbats—canbeimprovedbyincorporatinginformation
regardingthebattingaveragesforthefirstforty-fiveatbatsoftheotherseventeen
players.61Butwhyshouldthisbe?WhyshouldthebattingaveragesofMunsonor
Kessinger,whohad“first-forty-five”battingaveragesof.156and.289,respectively,have
anyinfluenceonourestimateofClemente’safter-forty-fivebattingaverage?Usingother
players’first-forty-fivebattingaverageswouldseemobviousintheabsenceofClemente’s
first-forty-fiveaverage;butwehaveClemente’sfirst-forty-fivebattingaverage—andwhat
couldbebetterthanthat?
Theexplanationliesintheinformationweobtainfromthefirst-forty-fivebatting
averagesoftheotherseventeenplayers.First,supposeweknownothingaboutbatting
59SeeBradleyEfron&CarlMorris,DataAnalysisUsingStein’sEstimatorandItsGeneralizations,70J.OFTHEAM.STATIST.ASS’N311,312-14(1975).
60Id.at313.
61Seeid.at312-14.
91
averages.Itseemsintuitivethat,inestimatingClemente’safter-forty-fivebattingaverage,it
ishelpfultoknowwhetherhisfirst-forty-fivebattingaverage,.400,is“low,”“high,”or
“average.”Inparticular,itseemshelpfultoknowthat.400isanextremelyhighbatting
average.Asanextremeexample,ifwearetoldthat,inagivenperiod,aparticularbatting
averageisthehighesteverachievedbythatplayer,orinbaseballingeneral,wouldwestill
usethisaverageasourbestestimateoftheplayer’saverageinthenextperiod?Wewould
bewisetoincorporatethisinformation,sincetheplayerisunlikelytobreakbaseball’sall-
timerecordtwiceinarow.Morespecifically,theusefulnessofother-playerinformation
canbeexplained,inpart,byconsideringtheoldidea(duetoSirFrancisGalton)of
“regressiontowardthemean,”which,initssimplestform,statesthatifweobtaina
relativelyextrememeasurement,thenuponre-measurement,wearelikelytoobtainanew
measurementclosertoaverage.62Thereasonissimple:anextrememeasurementcanbe
attributedtoacombinationoftwothings—thecharacteristicsofthethingmeasured(e.g.,
theskillofabaseballplayerwhowasinfactafarsuperiorbatterthanhispeers)and
randomvariation,or“luck.”Totheextentthattheextrememeasurementisdueto
randomness,itislikelytobelessextremeuponre-measurement.Similarly,information
regardingotherplayers’performanceprovidescontextforClemente’sperformance,andan
estimatorthatincorporatessuchinformationislikelybetterthanonebasedsolelyonthe
player’sindividualperformance.63
62SeegenerallyStephenM.Stigler,Darwin,GaltonandtheStatisticalEnlightenment,173J.R.STATIST.SOC’YA469(2010).
63Wecanconsidertwosourcesofvariability:thereisvariationamongtheplayers(somearebetterthanothers,forexample)and,givenaparticularplayer(andgivenhismeanbattingaverageinparticular),thereisvariationintheplayer’sbattingaverage.“Regressiontowardthemean”thusoperatesintwoways:First,
92
Inshort,ifwebelievethattheplayers’battingaveragesaresomehowbound
together,wecanmakesignificantestimationimprovementsbyincorporatingother-player
information.64
Returningtothelegalcontext,thevalueofadamagesaward(or,specifically,an
awardforpainandsufferingorpunitivedamages)canbeunderstoodasattributableto1)
theapplicationofthelawtotheparticularfactsofthecase,and2)randomvariation.In
ordertogainadeeperunderstandingofthebenefitsofCCG,letusmodelanaward
“hierarchically”toaccountforbothoftheforegoingelements.Asabove,weassumethatthe
actualaward𝛼isdistributedwithmeanαandvarianceσ2.Butnow,letusassumethatαis
itselfrandomratherthanconstant,andthatitisdistributedwithmeanµandvarianceτ2.
Notationally,𝛼~(𝛼, 𝜎))and𝛼~(𝜇, 𝜏)).Inwords,thehierarchicalmodelincorporates
variabilityontwolevels.First,theupperlevel 𝛼~ 𝜇, 𝜏) indicatesthatcasesare
heterogeneous—thattherecanbefactualvariabilityacrosscases,andthatthepresentcase
maybemateriallydifferentfrompriorcases.Irefertothisformofvariability,τ2,as“claim
variability.”65Second,thelowerlevel(𝛼~ 𝛼, 𝜎) )indicatesthat,giventhefactsofany
onthelattersource,pullingaplayer’sbattingaverageintowardhismeanbattingaverage;andsecond,onthe former source, pulling a player’s batting average in toward the league’s mean batting average.Incorporatinginformationregardingthedistributionofplayersallowsustoaccountforthepulltowardtheleague’smeanbattingaverage.
64Efron&Morrisdiscussconditionsunderwhichestimationimprovementscanbemadeevenwhentheestimands—thethingswewishtoestimate—arenotboundtogether.SeegenerallyEfron&Morris,supranote59;BradleyEfron&CarlMorris,Stein’sParadoxinStatistics,236SCIENTIFICAMERICAN119(1977).
65SeeBavli,supranote50,at74-78.
93
singlecase(forexample,thepresentcase),thereisvariability(i.e.,randomness)inthe
determinationofdamages.Irefertothisformofvariability,σ2,as“judgmentvariability.”66
Again,ourgoalistoarriveatagoodestimate𝛼ofα.Ononehand,wewantthe
estimatetoreflectthefirstformofvariability—thatmeaningfulfactualdifferences(e.g.,
betweenthepresentcaseandpriorcases)shouldresultindifferentawards.Ontheother
hand,wewanttominimizethesecondformofvariability—therandomnessassociated
withthedeterminationofdamagesinagivencase.Sohowdoesincorporatingprior-award
informationhelp?Unfortunately,sincewegenerallydonotknowthecorrectdamages
award,itisimpossibletodistinguishtheformerformofvariabilityfromthelatter.Inother
words,atradeoffarisesbetweenminimizingbias—thatourestimateddamagesaward
should,onaverage,beasclosetothecorrectdamagesawardaspossible,reflectingthe
formerformofvariability—andminimizingvariance,thedegreeofrandomnessassociated
withtheestimatedaward.Thus,inasense,incorporatingprior-awardinformationas
guidanceindeterminingadamagesawardallowsthetrieroffact(implicitly)tostrikea
balancebetweenbiasandvariancesoastominimizeerror.Byacceptingthepossibilityof
introducingsomebiasduetomaterialdifferencesbetweenthepresentcaseandprior
cases,itispossibletogainfarmore,intermsofreliability,duetothereductioninaward
variabilitythatfollowsfromsuchguidance.
Furthermore,theincorporationofprior-awardinformationshouldnotbeviewedas
sufferingfromcircularity—thatis,asamethodthatisdefeatedbyitsrelianceon
66Seeid.(discussing“judgmentvariability”and“claimvariability”);seealsoHillelJ.Bavli,SamplingandReliabilityinClassActionLitigation,2016CARDOZOL.REV.DENOVO207,210–12(2016).
94
informationthatentailsthesameflawsthatthemethodisitselfattemptingtoaddress.
Rather,suchmethodsshouldbeunderstoodasfacilitatingtheimprovementofawardsby
allowingforinformationsharingacrosscases.Intheframeworkdescribed,forexample,an
idealmethodforreducingerrorfromvariabilitywouldgenerateadamagesawardby
repeatedlyadjudicatingacasemanytimesindependentlyandusingthemeanofthe
repeatedadjudicationsastheultimateaward.Butsuchmethodsaregenerallyimpractical.
Methodsinvolvingtheincorporationofprior-awardinformationcanbeunderstoodas
efficientalternatives.Suchmethodsaimtocontrolvariabilitythroughinformation-sharing
acrossdifferentcases,ratherthanacrossreplicationsofthesamecase.Thecostofefficiently
reducingjudgmentvariability,however,isthepotentialforbiasarisingfromclaim
variability.
Inordertogainabetterunderstandingoftheeffectsofprior-awardinformationon
error,letusconsidertwoextremescenarios.First,supposethattheprior-award
informationis“dogmatic”inthesensethatitentirelydominatesthedamagesaward
withoutleavingroomforanyinfluencefromthefactsofthepresentcaseitself—for
example,supposethejurydecidesdogmaticallysimplytoapplytheaverageoftheprevious
awardsasitsawarddetermination,withoutconsiderationofthefactsofthecurrentcase.
Inthiscase,therewouldbenoerrorfromvariability,sincetheaverageoftheprevious
damageawardsisconstant;buttotheextentthattheaverageofthepriorawardsis
differentfromthecorrectcurrentawardα,therewouldbesubstantialerrorfrombias.On
theotherhand,supposethattheprior-awardinformationhasnoinfluenceonthecurrent
damagesaward—forexample,supposethejurydecidesdogmaticallythatitwillarriveat
95
anawarddeterminationbasedonthefactsofthecasealone,withoutinfluencefromprior
damageawards.Inthiscase,assumingjurydamagedeterminationsareinitially(i.e.,
withoutinfluencefrompriorawards)unbiased—thatis,theyachievethecorrectawardα
onaverage—thentherewouldbenoerrorfrombias,butsubstantialerrorfromvariability.
CCGimprovesthereliabilityofawardsforpainandsufferingandpunitive
damages—awardtypesthatsufferfromparticularlyhighdegreesofvariability—by
facilitatingabalancebetweenminimizingvariabilityandintroducingthepossibilityofbias.
Thequalityofthebalanceisdeterminedbythestrengthofthemethodforidentifying
comparablecasesanddistillinginformationforconsiderationbythetrieroffact.
Tobesure,letusconsidertwoimportantissues.First,assumingan“appropriate”
setofpriorcases,whatistheideallevelofinfluencethatshouldbeaffordedtoprior-award
information?Second,howcanwebecertainthatthepriorcasesidentifiedaresufficiently
comparabletothepresentcasesoastoimprovereliability?
Thefirstissue—theidealinfluenceofprior-awardinformation,assumingan
appropriatesetofpriorcases—dependsonthejudgmentvariability(σ2)oftheawardin
thepresentcaseandtheclaimvariability(τ2)ofthepriorcases.Higherjudgment
variabilitysuggestsweakerinformationobtainedfromthepresentcaseandgreater
influenceofthepriorawards;higherclaimvariabilitysuggestsweakerinformation
obtainedfromthepriorcasesandgreaterinfluenceofthepresentcase.
Forexample,consideratortcaseinwhichtheevidenceagainstthedefendantis
overwhelmingandthedamagesincurredbytheplaintiffareclear.Assumethatthe
evidenceissufficientlystrongthat,ifthecasewerelitigatedtentimesindependently,the
96
damageawardsinalltenreplicationswouldbeapproximatelythesame—say,$100,000.In
thiscase,theevidenceissogreatandthejudgmentvariabilitysolow(almostzero)that
thereislittletobegainedfromintroducingprior-awardinformationandthepossibilityof
bias.Ontheotherhand,consideracaseinwhich,althoughtheremaybestrongevidence
regardingthefactsofthecase,thereisonlyweakevidenceregardingtheappropriate
damagesaward—asisalmostalwaysthecaseforawardsforpainandsufferingand
punitivedamages.Ifthecasewererepeatedlyadjudicatedtentimesindependently,the
damageawardsacrossthetenreplicationswouldvarywildly.Inthiscase,thedamages
awardishighlyvariableandthereismuchtobegainedbyintroducingprior-award
information.Further,theprior-awardinformationisespeciallybeneficialifclaim
variabilityislowandpriorawardsprovideclearinformation.Forexample,assumethatthe
factsandlegalissuesinthepresentcaseareclear,andthatthecourtconfidentlyidentifies
asetoftencomparablecasesthatinvolvesimilarfacts—forexample,similarinjuries
arisingfromsimilarcircumstances.Assumefurtherthatthedamagesawardedintheten
casesareverysimilar—say,approximately$50,000.Inthiscase,inwhichjudgment
variabilityishighandclaimvariabilityislow,prior-awardinformationshouldhaveahigh
degreeofinfluence.67
67Moreformally,itcanbeshownthat,if,asabove,thedamagesaward𝛼isdistributedwithmeanαandvarianceσ2,andthe“correct”damagesawardαisdistributedwithmeanµandvarianceτ2(thus,ifwehavejudgment variabilityσ2and claimvariabilityτ2), then theoptimal damages awardweights current caseinformationby1/σ2andprior-awardinformationby1/τ2.Inotherwords,theidealinfluenceofthepriorawards(andparticularlythemeanofthepriorawards)isinverselyproportionaltotheclaimvariability(τ2) of the prior awards relative to the judgment variability (σ2) of the award in the present case. Seegenerally Efron & Morris, supra note 59; W. James & Charles Stein, Estimation with Quadratic Loss, 1PROCEEDINGSOFTHEFOURTHBERKELEYSYMPOSIUM361(1961).Notethatsincewecannot,inpractice,knowthevalueofµ,themeanofthecorrectawards,weinsteadestimateµusingthemeanofthepriorawards,and
97
Itisworthreemphasizingherethatitisincorrecttoconclude,asnumerous
commentatorshave,that,becausepriorawardsmaysufferfromthesamearbitrariness
thatweaimtoaddressinthepresentcase,CCGwouldbeineffectiveinreducing(or,worse,
wouldcompound)awardvariability.Evenassumingthe(not-unlikely)scenariothat
judgmentvariabilityisapproximatelyequalacrosscases(asIhaveassumedabove),the
foregoinganalysismakesclearthattheidealinfluenceofprior-awardinformationcan
neverthelessbeveryhigh.Inotherwords,CCGmayneverthelesssignificantlyreduce
variabilityandimprovereliability.Thismakessense,sinceCCGallowsforthesharingof
informationacrossnumerous(althoughvariable)cases;itprovidessignificantguidance
whererelevantinformationisotherwisescarce.
Consideranextremeexampleinwhichjudgmentvariabilityisextremelyhighforall
cases(thepriorcasesaswellasthepresentcase)andclaimvariabilityisextremelylow.
Here,althoughpriorawardssufferfromthesameextremearbitrarinessthatweaimto
addressinthepresentaward,acourtwouldbenefitimmenselyfromCCGmethods.
Specifically,becauseclaimvariabilityisextremelylow,theprior-awardinformation
obtainedherewouldbeapproximatelyequivalenttoprior-awardinformationthatcouldbe
obtainedfromthe“ideal”proceduredescribedabove,wherebyadamagesawardis
calculatedbyaveragingoverawardsobtainedfromrepeatedindependentadjudications
(withdifferentjuries,judges,lawyers,presentationsoftheevidence,etc.)ofasinglecase,
“shrink” toward this value. We can estimate the variance terms as well. Notationally, the “shrinkage
estimator”canbewrittenas𝛼U =ij-G kl-
mj-G ml-.
98
thecaseathand.Theawardsobtainedfromrepeatedadjudicationswouldvary
considerably,sincejudgmentvariabilityisextremelyhigh.Buttheultimateaward,
calculatedbyaveragingalloftheawardsobtainedfromtherepeatedadjudications,is
extremelyprecise—itissubjecttoalmostnovariability.
Assuggestedabove,methodsinvolvingrepeatedadjudicationareidealbutcostly.
CCGmethodsareefficientalternativesthatcomeatthecostofpossiblebiasthatmayarise
dueto“misalignment”—wherethemeanofthecorrectawardsinthepriorcasesis
differentfromthecorrectawardinthesubjectcase—andperhapsduetoclaimvariability,
orheterogeneityinthesetofpriorcases.68Inourcurrentexample,however,biasisnota
problem,becausethereisnomisalignmentproblemandclaimvariabilityisassumedtobe
extremelylow.Thus,althoughthepriorawardsaresubjecttoextremelyhighjudgment
variability,intheaggregatetheyallowforanextremelyreliableoutcomethroughthe
sharingofinformationacrosscases.Furthermore,wecanrelaxtheassumptionof
extremelylowclaimvariability.Higherclaimvariabilitymaycausebias;buttheharmto
reliabilityassociatedwithanyintroductionofbiasisoftenwelloutweighedbythe
reliabilitybenefitsassociatedwiththereductioninjudgmentvariability.Inanycase,the
introductionofclaimvariabilitydoesnotaffecttheconclusionthatCCGmethodsare
effectiveinreducingjudgmentvariabilityandimprovingreliabilitynotwithstandingthe
potentialarbitrarinessassociatedwiththepriorawards.
68Seeinfranote81.
99
Thesecondissue—thereliabilitybenefitsofCCGinlightoftheactualcomparability
ofthepriorawards—dependsonwhetherthepotentialforbiasisoutweighedbythe
benefitsofreducingvariability.Thisisavalidconcerninthesensethatthereliability
benefitsofCCGareindeeddependentonthematerialcomparabilityofthepriorcasesto
thepresentcase.
Fortworeasons,however,thelikelihoodofidentifyingasetofcasessufficiently
inappropriate,relativetothepresentcase,toharmreliabilityisverylow.First,because
awardsforpainandsufferingandpunitivedamagesarehighlyvariable,thepotential
reliabilitybenefitsofCCGaregreat.Asdiscussedabove,thehigherthevariabilityofthe
award,thegreaterthepotentialbenefitsofCCG,andthegreaterourtoleranceforbias.The
potentialforharmfrombiasarisingfrommisalignmentwouldbemoreconcerning,for
example,ifacourtwereinterestedinapplyingprior-awardinformationtoreducethe
already-lowvariabilityofanawardforacertaintypeofeconomicdamages.However,the
highvariabilityofawardsforpainandsufferingandpunitivedamages—sufficientlyhighto
promptdrastic(andhighly-biasing)measuressuchasdamagecaps—suggeststhatthe
benefitswithrespecttovariabilityarelikelytodominateanybiasarisingfrom
misalignment(oranynegativeeffectsarisingfromhighclaimvariability).
Second,thebiasintroducedbyCCGmethodsislikelytobelow.Statistically,the
appropriatenessofasetof“comparable”cases,relativetothepresentcase,involvesthree
majorfactors:1)the“alignment”ofthemeanofthe“correct”awardsinthepriorcases
withthe“correct”awardinthepresentcase,2)thevariabilityofthecorrectawardsinthe
priorcases,and3)thenumberofpriorcases,orthe“samplesize.”Inpractice,acourt
100
shouldbeconcernedwiththealignmentofthematerialfactsofthepriorcaseswiththose
ofthepresentcase,thesubstantivebreadthofthepriorcases,andthesamplesize.
Notethatwecannotperfectlypredicthowatrieroffactwillinfactincorporate
guidancefrompriorawards.Forpurposesofthisdiscussion,andfortheguidanceIprovide
inSection5belowregardingthedevelopmentofcomparable-caseinformation,Iassume
thatthetrieroffactwillnotact“irrationally”byaffordingmoreinfluencetohighly-
dispersedpriorawardsthantominimally-dispersedpriorawards.Itisnotnecessaryfor
thetrieroffacttobehaveperfectlyrationally,buttheforegoingassumptionprovidesa
goodstartingpointforguidance.We“trust”thetrieroffacttoactapproximatelyrationally
innumerouslegalcontexts;andindevelopingguidanceforthetrieroffact,thecourt
arguablyshouldassumesomedegreeofrationality,asitdoesinprovidingotherformsof
guidance.
Statistically(usingfundamentalsof“shrinkageestimation”),incorporatingprior-
awardinformationwillgenerallyimprovereliability,aslongasthepriorawardsarenot
tightlybound(i.e.,withlowvariability)aroundameanthatisfarfromthecorrectawardin
thepresentcase69—inpractice,aslongasthepriorawardsarenottightlyclusteredaround
anawardthatreflectsfactsmateriallydissimilartothepresentcase.
Highprior-awardvariabilityitselfis(absentextremeconditions)unlikelytoharm
thedamagesaward,sincethevariabilityofawardsforpainandsufferingandpunitive
damagesishigh,and,assuggestedbythediscussionabove,theweightaffordedtheprior-
69SeegenerallyEfron&Morris,supranote59;James&Stein,supranote67.
101
awardinformation(and,statistically,themeanofthepriorawardsinparticular)is
proportionaltotheinverseofthevariabilityofthepriorawards.Thismeansthathighly
dispersedpriorawards(e.g.,priorawardsthatspanawiderangeofvalues)willhavelittle
influenceontheawarddetermination(inthemodelabove,𝛼Uwillbeapproximatelyequal
to𝛼).
Additionally,althoughuncomparablepriorcasescancausesignificantbias,this
concernfadeswhenweconsidertherelativelyremoteconditionsnecessaryforCCGto
harmreliability,inthesenseofincreasingawarderror.Inparticular,forCCGtoharm
reliability,itwouldgenerallyrequireacombinationofsignificantlydissimilarcasesand
lowprior-awardvariability—acombinationthatishighlyunlikelyifthepriorcasesare
specificallyselectedtobecomparabletothepresentcase,andwherethevariabilityofthe
awardscanoftenreflect(andperhapsshouldreflect)thecourt’slevelofconfidence
regardingthecomparabilityofthepriorcasestothepresentcase.70
Inshort,wecanexpectthatareasonablemethodforidentifyingprior“comparable”
caseswillresultinprior-awardinformationthatislikelytoimprovereliability.71Ofcourse,
themorecomparablethepriorcasesaretothepresentcase,thebettertheguidanceforthe
trieroffact,andthegreaterthereliabilitybenefits.Inthefollowingsection,Idiscussin
greaterdetailthedevelopmentofcomparable-caseinformation.
70SeeSection5foradiscussionofmethodsforselectingcomparablecases.
71A formalderivationof theparticularmeanandvariabilityconditions thatwouldcauseareduction inreliabilityisbeyondthescopeofthecurrentarticle.
102
5. DevelopingComparable-CaseInformation
Inthissection,Idiscussanumberofconsiderationsforestablishingcomparable-
case(or“prior-award”)information.Iaddresstwoareasofconcern:1)identifyingasetof
materially“comparable”cases,and2)distillingcomparable-caseinformationfromthese
casesforconsiderationbythetrieroffact.
5.1 Identifying“Comparable”Cases
TouseCCG,acourtmustidentifyasetofcomparablecases.Assuggestedabove,a
courtshouldbeconcernedwiththreefactors:thealignmentofthepriorcaseswiththe
subjectcase,thebreadthofthepriorcases,andthenumberofpriorcases.Thesuitabilityof
thecasesandexpectedbenefitsoftheguidancedependonthecourtscareinbalancing
thesefactors.Forexample,priorawardswithlowerbreadthgenerallyproduce,inasense,
more“specific,”andthereforemoreinfluential,guidance;butlowerbreadthalsoresultsin
asmallersamplesize,whereasalargersampleprovidesmoreinformationandtherefore
betterguidance.Additionally,thealignmentofthepriorcasesaffectsthebiasintroduced
bythepriorawards,andthebreadthofthepriorcases,whichaffectstheweightor
influenceofthepriorawards,mayreflectthecourt’sconfidenceinthealignmentofthe
casesidentified.
Intermsofalignmentandbreadth,themostsignificantfactoraffectingacourt’s
identificationofpriorcasesislikelyitsunderstandingofthesubjectcaseandwhichfacts
andissuesarefundamentaltoanappropriatecomparison.
Consider,forexample,JudgePosner’sanalysisinJutzi-Johnson.Thatcaseinvolved
allegationsthatajailwasnegligentinfailingtoidentifyaprisonerasasuicideriskandtake
103
precautionarymeasures,resultingintheprisonerhanginghimself.Commentingonthe
parties’identificationofcomparisoncases,JudgePosnerexplained:
Theplaintiffcitesthreecasesinwhichdamagesforpainandsufferingrangingfrom $600,000 to $1million were awarded, but in each one the pain andsufferingcontinuedforhours,notminutes.Thedefendantconfineditssearchfor comparable cases tootherprisonsuicidecases, implying thatprisonersexperiencepainandsufferingdifferentlyfromotherpersons,sothatitmakesmoresensetocompareJohnson’spainandsufferingtothatofaprisonerwhosuffered a toothache than to that of a free personwhowas strangled, andconcludingabsurdly thatanyaward forpainandsuffering in this case thatexceeded $5,000 would be excessive. The parties should have looked atawardsinothercasesinvolvingasphyxiation,forexamplecasesofdrowning,whicharenumerous....Hadtheydoneso,theywouldhavecomeupwithanawardintherangeof$15,000to$150,000.72
JudgePosnerthusdisagreedwiththealignmentoftheplaintiff’scases,which
involvedpainandsufferingthatcontinuedforhoursratherthanminutes.Healsodisagreed
withthealignment,aswellasthebreadth,ofthedefendant’scases,whichwere“confined”
to“otherprisonsuicidecases”—asthough“prisonersexperiencepainandsuffering
differentlyfromotherpersons”—leadingto“absurd”conclusionsregardingasuitable
award.73Finally,JudgePosnerdisplayedconcernforsamplesize,suggestingthatwidening
thebreadthofthepriorcasestothoseinvolvingasphyxiationwouldhaveresultedin
“numerous”priorcasesforcomparison.74Samplesizeisimportantbecausepriorawards
aresubjecttojudgmentvariability:ifacourtselectsonlyasinglecaseforcomparison,then,
evenifthecourtisextremelyconfidentthatthepriorcaseisindeedcomparable,itwould
remainunclearwhethertheawardinthatcaseisduetothespecificfactsofthecaseorto
72Jutzi-Johnsonv.UnitedStates,263F.3d753,760-61(7thCir.2001).
73Id.
74Id.
104
randomness.Acourtmaybejustifiedinsacrificingsomedegreeof“comparability”for
purposesofincreasingthesamplesize.Ofcourse,inpractice,acourtmaydeterminethat
thematerialfactsofacasearetoouniqueforcomparison,andmayaccordinglyforegoany
applicationofCCG.
Withthesefactorsinmind,thecourtshouldarriveataprocessforselectinga
suitablesetofpriorcases.Selectionmethodsshouldremainflexiblesothatcourtsmay
catersuchmethodstotheuniquecircumstancesofthecaseathand.Initially,courtscan
obtainguidancefromcomparativeapproachesusedregularlytodeterminedamagesin
variouscivilcontexts.75
Thus,considerasimpleprocedureinwhichthecourtaskseachpartytoidentifya
setof“comparable”cases.Suchaprocedureislikelytoresultinasetofextreme(although
perhapsunbiased)cases,sinceeachpartyselectscasestomaximizeitsowninterests.76On
theotherhand,amethodbywhichthecourt,ratherthantheparties,selectsasetof
“comparable”casesislikelytoproducelessvariability,butissusceptibletoanumberof
drawbacks,includingthepotentialforjudicialbiasandundueburdenonthecourt.
Alternatively,thecourtmaydirectthepartiestoagreeonasetofpriorcases;butthismay
bedifficultandinefficientwithoutadditionalstructurefromthecourt.77
75 See infra Section 6. Courts may also obtain guidance from the class action context, where courtssometimesselectasetof“representative”or“bellwether”casesforsettlementorlitigationpurposes.SeegenerallyBavli,supranote50.
76SeegenerallyLorenH.Brownetal.,BellwetherTrialSelectioninMulti-DistrictLitigation:EmpiricalEvidenceinFavorofRandomSelection,47AKRONL.REV.663,674-75(2014).
77Seegenerallyid.at675.
105
Althoughthecircumstancesofaparticularcasemaycallforoneofthemethods
above,aparticularlyusefulapproachisoneinwhichthecourtselectsafinalsetofcases
fromapoolidentifiedbythelitigants.Variationsofthismethodhavebeenusedinvarious
civilcontexts.78Itallowsforsignificantflexibility,andbenefitsfrombothalitigant-based
selectionprocessandtherelativeobjectivityofthejudge.
Finally,itispossibletoinclude(implicitly)thetrieroffactintheselectionprocess
byprovidingitwithqualitativeinformationregardingthesetofcomparablecases,thus
allowingittoweighttheprior-awardinformationbased,inpart,onitsassessment
regardingthealignmentofthepriorcases.Idiscussthispossibilityfurtherinthefollowing
subsection.
5.2 DistillingComparable-CaseInformation
Oncethecourthasselectedasuitablesetofpriorcases,itmustdecidewhat
informationshouldbeconsideredbythetrieroffactasguidance.AstudybyProfessor
MichaelSaksetal.examinedtheeffectsofvariousformsofjuryguidanceonamounts
awardedforpainandsufferinginpersonalinjurycases.79Theyfoundthat,whiledamage
capsperformedpoorlyintermsofvariabilityanddistortionofawardmagnitude,various
formsofdistributionalinformation—inparticular,an“awardinterval,”an“awardaverage-
plus-interval,”and“awardexamples”—wereeffectiveinreducingvariabilitywhile
78See infraSection6; see alsoBrownet al., supranote76, at 672-76 (describing cases employing suchproceduresinthebellwethercontext).SeegenerallyAlexandraD.Lahav,TheCasefor“TrialbyFormula”,90TEXASL.REV.571(2012).
79SeeSaksetal.,supranote15.
106
distortingawardmagnitudeminimallyornotatall.80Theseresultssupportthemodel
describedinSection4.Inparticular,inlinewiththeanalysisabove,prior-award
informationisexpectedtocauseareductioninvariabilityandminimal(ifany)distortionof
awardmagnitudewherethedistributionofprior-awardsissimilartothedistributionthat
wouldbeobtainedintheabsenceofprior-awardinformation.Indeed,Saksetal.obtained
thevaluesoftheguidanceprovidedtosurveyparticipantsfromtheresultsoftheirpilot
study.Specifically,theyusedthemedianofthepilotstudyfortheawardaverage,the10th
and90thpercentilesfortheawardinterval,the10th,50th,and90thpercentilesforthe
awardaverage-plus-interval,andthe10th,35th,65th,and90thpercentilesfortheaward
examples.81
ThediscussioninSection4suggeststhatcourtsshouldchooseinformationforms
thatprovidejurorswithinformationregardingthe“center,”aswellasthe“spread,”or
variability,ofthedistributionofthepriorawards.82Theawardinterval,awardaverage-
plus-interval,andawardexampleshavetheadvantage,relativetoproviding,forexample,
onlytheawardaverage,thatjurorsareprovidedinformationregardingthevariabilityof
thepriorawards.Thisenablesthemtoweighttheprior-awardinformationappropriately.
Theawardexamplesformisparticularlyappealing,becauseitprovidesjurorswiththe
80Seeid.at249-55.Saksetal.observedmixedresultsforthe“awardaverage”form.Seeid.at253-55.
81Id.at248.Theauthors’resultsforthecapcondition,whichcausedadistortioninthesize,ormagnitude,oftheawardandmixedeffectsonvariability(dependingontheseveritycategory)canbeinterpretedassupportiveofthemodelherein,butmayalsohaveimplicationsfortheeffectsofprior-awardinformation.
82Itispossiblethat,empirically,jurorswillnotinfactweighttheprior-awardinformationaccordingtotherelative variability of such information; butwithout significant evidence to the contrary, courts shouldarguablyprovidejurorswithrelevantvariabilityinformation.
107
mostinformation,relativetotheotherinformationforms,regardingprior-award
variability.
Further,inadditiontonumericalprior-awardinformation,itmaybebeneficialfor
thecourttoallowthetrieroffacttohearqualitativesummaryinformationregardingthe
priorcases.Providingthetrieroffactwithsuchinformationwouldstrengthenitsrolein
thepossiblyfact-intensiveidentificationprocess,andwouldmitigatetheeffectsof
potentialbiasfrommisalignment.Assuggestedabove,providingthetrieroffactwith
qualitativecaseinformationimplicitlyincludesitinthecase-selectionprocessbyenabling
ittoweighttheprior-awardinformationbased,inpart,onitsassessmentofthe
comparabilityofthepriorcases.83
Ifthecourtallowsthetrieroffacttohearqualitativecaseinformation,itmust
determineanappropriateformforsuchinformation—forexample,abriefdescription
regardingthesetofcasesasawhole,orasetofshortfactualsummariesregardingeach
individualcase.
AsdescribedinSection6below,thereissubstantialprecedentforallowingajuryto
hearcomparable-caseinformationintheformofevidenceintroducedasexperttestimony.
Ajurymaythereby“consider...argumentsabouttheeffectof[purporteddifferences]on
thevalidityof[the]comparisonand...adjustitsdamageawardaccordingly.”84
83Thecourtshouldbalancethebenefitsofallowingqualitativecaseinformationwiththecosts(includingattorneys’fees,delays,etc.)ofallowingsuchinformation.
84SyufyEnterprisesv.AmericanMulticinema,Inc.,793F.2d990,1003(9thCir.1986).
108
6. Conclusion
Intheprevioussections,IaddressedthreemajorobjectionstoCCGmethods.First,I
explainedthatCCGcanreduceunpredictabilityandimprovethereliabilityofawards—
notwithstandingthejudgementvariabilityassociatedwiththepriorawards—byallowing
forthesharingofinformationacrosscases.Second,Idiscussedhowinformationregarding
awardsincomparablecasescanbeunderstood,notasanalternativetoassessingdamages
forpainandsufferingoranappropriatepunitivedamagesaward,butasfundamentalto
assessingsuchvalues.Finally,Iexplainedthatitisnotnecessaryforthepriorcasestobe
perfectlycomparabletothesubjectcase,andthat,assumingareasonablemethodfor
identifying“comparable”cases,itisunlikely—particularlyforawardsforpainand
sufferingandpunitivedamages—thattheywilldiminish,ratherthanimprove,reliability.
Moreover,itisimportanttounderstandthatusingcomparable-caseinformationas
guidanceindeterminingawardsforpainandsufferingandpunitivedamagesisnota
remoteconceptthatrequiresdramaticchangetocurrentpractices.Indeed,courtshave
recognizedtheimportanceofcomparable-caseinformationasguidanceindetermining
awardsinarangeofcontexts.
First,thereissubstantialprecedentfromthejudicial-reviewcontextforallowing
informationregardingpriorawardstoinfluencepresentawardsand,inparticular,forthe
useofcomparable-caseinformationasguidanceindetermininganappropriateawardor
rangeofawards.Indeed,courtshavedescribedthecomparisonofawardstopriorawards
forsimilarinjuriesas“[a]mainstayoftheexcessivenessdetermination,”notingthat“[t]his
useofcomparisonisarecognitionthattheevaluationofemotionaldamagesisnotreadily
109
susceptibleto‘rationalanalysis.’”85Forexample,courtsinNewYorkhaveheldthat,in
determiningwhetheranawardisexcessive,areviewingcourtmustconsiderawardsin
comparablecases86—thatthe“determinationofwhetheracompensatorydamagesaward
isexcessiveshouldnotbeconductedinavacuum,butinsteadshouldincludeconsideration
oftheamountsawardedinother,comparablecases.”87TheU.S.SupremeCourthasitself
indicated,inthecontextofdeterminingwhetheraparticularpunitivedamagesaward
exceededtheamountpermittedbytheDueProcessClauseoftheConstitution,that
“[c]omparingthepunitivedamagesawardandthecivilorcriminalpenaltiesthatcouldbe
imposedforcomparablemisconductprovidesa[n]...indiciumofexcessiveness.”88
Second,thereissubstantialprecedentfromthebench-trialcontextforCCG—and
specifically,forconsiderationofcomparable-caseinformationbythetrieroffactfor
guidanceindeterminingawardsforpainandsufferingandpunitivedamages.Infact,
85Salinasv.O’Neill,286F.3d827,830-31(5thCir.2002)(internalcitationsomitted).
86Allav.Verkay,979F.Supp.2d349,372(E.D.N.Y.2013)(emphasisadded).
87DiSorbov.Hoy,343F.3d172,183(2dCir.2003)(internalquotationmarksandcitationsomitted).SeeGeressyv.DigitalEquip.Corp.,980F.Supp.640,656(E.D.N.Y.1997)aff’dinpartsubnom.Maddenv.DigitalEquip.Corp.,152F.3d919(2dCir.1998)(“CPLR5501(c)’sconceptionofreasonablecompensationcannotexistinavacuum.Thereneedstobesomepointofreference.Witheconomicdamages,thecourtmayrelyon traditional methods of economic analysis. As for the non-economic pain and suffering award, thereviewingcourtmustbeginbyidentifyingsomegroupofsimilarcasestoserveasareferent.Thistaskisdifficult, particularly in cases exploring relativelynew types of injuries and claims such as those in theinstantcaseinvolving[repetitivestressinjury(RSI)]claimsagainstakeyboardmanufacturer.Caseswithsimilar causal agents, similarly-nameddiagnoses, or similar reductions in quality of lifemight serve asbenchmarks.”).
88SeeBMWofN.Am.,Inc.v.Gore,517U.S.559,583(1996).SeealsoDegorskiv.Wilson,No.04CV3367,2014WL 3511220, at *1 (N.D. Ill. July 16, 2014) (“In assessing whether a punitive damage award isconstitutionally appropriate, the Supreme Court has directed courts to focus their evaluation on threeguideposts:(1)thereprehensibilityofthedefendant’sconduct;(2)therelationshipbetweentheamountof thepunitivedamages awardedand theharmorpotential harmsufferedby thePlaintiff; and (3) thedifference between the punitive damages award and the civil penalties authorized or imposed incomparablecases.”).
110
considerationofcomparable-caseinformationisoftenexpected.Forexample,inJutzi-
Johnson,JudgePosnerremarkedthatmostcourts“treatthedeterminationofhowmuch
damagesforpainandsufferingtoawardasastandardless,unguidedexerciseofdiscretion
bythetrieroffact,reviewableforabuseofdiscretionpursuanttonostandardtoguidethe
reviewingcourteither.”89Headvised:
Tominimize the arbitrary variance in awards bound to result from such athrow-up-the-handsapproach,thetrieroffactshould...beinformedoftheamountsofpainandsufferingdamagesawardedinsimilarcases.Andwhenthe trier of fact is a judge, he should be required as part of hisRule 52(a)obligationtosetforthinhisopinionthedamagesawardsthatheconsideredcomparable. We make such comparisons routinely in reviewing pain andsufferingawards,asdoothercourts.Itwouldbeawisepracticetofollowatthetriallevelaswell.90
Third,thereisprecedentfromvariouscivilcontextsforaskingjurorstomake
comparisonsforpurposesofdeterminingdamages.Thecomparisonsoftenrelatetogoods
orservicesforwhichthereisaneconomicmarket,andthecomparisonsareundertakenfor
purposesofprovidinginformationregardingthemarket,which,inturn,provides
informationregardingtheappropriatedamagesaward.
Forexample,inthecontextofdetermining“justcompensation”ineminentdomain
litigation,itiscommonforacourttoaskthejurytoundertakea“comparablesales”
89Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001).
90Id.;seealsoArpinv.UnitedStates,521F.3d769,776-77(7thCir.2008)(explainingthatthelowercourt“shouldhaveconsideredawardsinsimilarcases,bothinIllinoisandelsewhere,”andthat“[c]ourtsmaybeabletoderiveguidanceforcalculatingdamagesforlossofconsortiumfromtheapproachthattheSupremeCourt has taken in recent years to the related question of assessing the constitutionality of punitivedamages”);Zurbav.UnitedStates,247F.Supp.2d951,961(N.D. Ill.2001)aff’d,318F.3d736(7thCir.2003)(consideringawardsin“comparable”cases);Elkv.UnitedStates,87Fed.Cl.70,97(2009)(“[v]ariouscases,includingthosearisingundertheFTCA,suggestthatjudgesfacedwiththeprospectofdeterminingpainandsufferingawardsshouldlooktotheawardsinsimilarcases”);Cochranv.A/HBatteryAssociates,909F.Supp.911,917(S.D.N.Y.1995)(“courtshavelongrevieweddamageawardsinothersimilarcasestodeterminethescopeofreasonablenessinaparticularcase”).
111
analysis,forwhichthejuryhearstestimonyregardingthesellingpriceofcomparable
properties.91Insuchcases,thecourtintendstoprovidethejurywithinformation
regardingthemarkettowhichthepropertyatissuebelongs,andtherebyfacilitatethe
jury’sassessmentofjustcompensationandthusanappropriatecompensatorydamages
award.Indeed,comparablesalesevidenceisoftenviewedasthe“bestevidence”ofmarket
value.92Similarly,damageawardsforbreachesofcontractforthesaleofgoodsorservices
areoftencomputedbylookingatthemarketpriceofcomparablegoodsorservices.93And
courtsalsorelyonthejurytomakecomparisonsinarrivingatdamagescalculationsinthe
antitrustcontext.94
91SeeUnitedStatesv.1,129.75AcresofLand,MoreorLess,inCross&PoinsettCtys.,473F.2d996,998(8thCir. 1973) (citing cases, and holding that, “[g]enerally, evidence of sales of comparable property ispersuasiveevidenceofmarketvalue,eitherasdirectprooforinsupportofawitness’sopinion”).
92 SeeUnited States v. 24.48Acres of Land, 812 F.2d 216, 218 (5th Cir. 1987) (“First,we reiterate theprinciplethatthebestevidenceofmarketvalueiscomparablesales”)(citingUnitedStatesv.8.41Acres,680F.2d 388, 395 (5th Cir. 1982)). See also John J. Dvorske & Ann K.Wooster, Condemnation of Property,ComparableSales,7FED.PROC.,L.ED.§14:90(December2015).
93U.C.C.§2-713(“themeasureofdamagesfornon-deliveryorrepudiationbytheseller[ofgoods]isthedifferencebetweenthemarketpriceatthetimewhenthebuyerlearnedofthebreachandthecontractpricetogetherwithanyincidentalandconsequentialdamagesprovidedinth[e]Article(Section2-715),butlessexpensessavedinconsequenceoftheseller’sbreach”).SeealsoGulfPowerCo.v.CoalsalesII,LLC,522F.Appx.699,707(11thCir.2013)(holding,inacaseinvolvingabreachofacontractforthepurchaseandsaleofcoal,that“theappropriatemeasureofdamageswouldbethemarketremedyprovidedforin§672.713[oftheU.C.C.],inwhichdamagesarecalculatedbycomparingthecontractpricetothefairmarketvalueofcomparablegoodsontheopenmarket”).
94Forexample,inSyufyEnterprisesv.AmericanMulticinema,Inc.,793F.2d990(9thCir.1986),counterclaimantAMCbaseditsdamagescalculationoncomparisonswithpurportedlycomparablemarkets.Itpresentedsuchcomparisonstothejury,whichultimatelyrenderedanawardaccordingly.Seeid.at1002-03.TheNinthCircuitrejectedtheargumentthatdamagesmaynotbecomputedbasedoncomparablemarkets.Seeid.ThecourtthenrejectedtheargumentthatthecomparisonmarketswerenotcomparabletothemarketatissueandtherebyinappropriatelyinflatingAMC’sdamagescalculation.Seeid.at1003.Thecourtheldthat“[c]omparabilityisaquestionoffact”andthat“[i]twasforthejurytoconsider[theopposingparty’s]argumentsabouttheeffectofthe[claimeddifferences]onthevalidityofcomparisonandtoadjustitsdamageawardaccordingly.TherewassufficientevidencetoallowajurytorenderadamageawardforAMConthebasisofthecomparison....”Id.
112
AdetailedexaminationofthelegalfoundationsofCCGisbeyondthescopeofthis
article.Thelegalcontextaboveisintendedsimplytoshowthatthereisalonghistory,
acrossvariouscontexts,ofusingcomparable-caseinformationasguidanceindetermining
damages.Indeed,courtshaveappliedsuchmethodsnotwithstandingtheobjections
addressedinthisarticle.Forexample,considertheobjectionthatcourtswillcompoundthe
arbitrarinessofawardsbyobtainingguidancefrompriorawardsthatpresumablysuffer
fromthesamearbitrarinessthatcourtshopetoaddress.Thisobjectionappliessimilarlyto
comparable-caseinformationconsideredinthebench-trialcontext,butbench-trialjudges
neverthelessconsidercomparable-caseinformation.Additionally,theobjectionthat
methodsinvolvingtheuseofpriorawards“failtoaddressthefundamentalissueofhow
oneshouldinitiallyassessthevalueofpain-and-sufferingdamages”95orarriveatan
appropriatepunitivedamagesawardappliessimilarlytotheuseofcomparable-case
informationinthejudicial-reviewandbench-trialcontexts;butsuchinformationisstill
usedinthesecontexts.Finally,theobjectionthatthevalidityofmethodsinvolving
comparable-caseinformationreliesheavilyonthepresumptionthatthepriorcases
identifiedareindeedmateriallycomparabletothepresentcaseappliessimilarlytoallof
thecontextsdiscussedabove;96butsuchmethodsareneverthelessused.
MyaiminthisarticlewastoaddressthemajorobjectionstoCCGmethodsby
explainingsimply,butformally,whatmanycourtsandcommentatorshaverecognized
95Avraham,supranote19,at104.
96Theobjectionappliesdirectlytothejudicial-reviewandbench-trialcontextsandanalogouslytothemarket-comparisonscontext.
113
implicitly:thatCCGiseffectiveinreducingunpredictabilityandimprovingthereliabilityof
awardsforpainandsufferingandpunitivedamagesbyallowingforthesharingof
informationacrosscases.
114
IV. ShrinkageEstimationintheAdjudicationofCivilDamageClaims*
(Coauthor:YangChen)
1. Introduction
Alegalproceedingcanbeunderstoodasaprocedureforgeneratinganoutcomethat
servesasanestimateofthe“correct”outcomeassociatedwithalegalclaim.Inthissense,a
criterionformeasuringthestrengthofalegalprocedureisreliability:thedegreetowhich
theprocedurecanbeexpectedtogenerate“accurate”outcomes,outcomesthatareclosein
proximitytothe“correct”outcome.1Intworecentarticleswrittenbyoneoftheauthors,it
isarguedthatcertainclaimaggregationmethods,methodsinwhichtheoutcomeofaclaim
isbasednotonlyonthecharacteristicsoftheclaimitself,butalsoontheoutcomesofother
claims,canimproveoutcomesgenerally.Thefirstarticleexaminestheconditionsunder
whichsamplingprocedurescanimproveaccuracyintheclassactioncontext,2whilethe
secondarticleexaminestheuseofcomparable-caseguidance(CCG),or“prior-award
information”—informationregardingawardsincomparablecasesasguidancefor
determiningdamageawards—toimproveaccuracyintheindividual-claimcontext.3
*HillelJ.Bavli&YangChen,ShrinkageEstimationintheAdjudicationofCivilDamageClaims,REV.OFL.&ECON.(forthcoming,2017).Inwritingthispaper,theauthorsbenefittedfromtheguidanceofDonaldB.RubinandJunS.Liu.
1HillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation.14LAW,PROBABILITY&RISK67(2015)[hereinafterAggregatingforAccuracy];HillelJ.Bavli,SamplingandReliabilityinClassActionLitigation,2016CARD.L.REV.DENOVO207[hereinafterSamplingandReliability].
2SeeAggregatingforAccuracy.
3HillelJ.Bavli,TheLogicofComparable-CaseGuidanceintheDeterminationofAwardsforPainandSufferingandPunitiveDamages,U.CIN.L.REV.(Forthcoming,2017)[hereinafterTheLogicofCCG].
115
Althoughsamplingandcomparable-caseguidancearequitedistinctinpractice,andarisein
differentcontexts,theunderlyingmechanismsbywhichtheyaffectaccuracyaresimilar.
Samplingproceduresinvolveadjudicatingaproportionofclaimsinaclassaction
(theclaimsinthe“samplegroup”)andextrapolatingdamageawardsfortheremaining
claims(theclaimsinthe“extrapolationgroup”).CCGmethodsinvolveincorporating
informationregardingawardsinpriorcomparablecasesintheadjudicationofadamages
awardinthesubjectcase.Samplingallowsforthesharingofinformationacrossclaimsina
class,whereasCCGallowsforthesharingofinformationacrossindividualclaims—but
bothmethodsaggregateanduseinformationregardingawardsincomparableclaimsto
influenceawardsofotherclaims.
Inthecurrentarticle,weexamineathird,butcloselyrelated—andinasense
unifying—formofclaimaggregationthatintegratessuchinfluenceexplicitly.Thisformof
claimaggregationisbasedonastatisticaldevicecalled“shrinkageestimation”(or
“shrinkage”),whichisusedinstatisticstoaggregateinformationandtherebyimprove
estimation.Specifically,itinvolvesadjustinganestimateofsomevaluetoaccountfor
informationderivedfromthepopulationofunitsfromwhichthatvalueisdrawn.4CCG,
whichusesinformationregardingcomparableclaimstoinfluencethesubjectclaim,canbe
understoodasaformofshrinkage.Similarly,samplingconstitutesaspecialcaseof
shrinkage,wherethepopulationofunitsistheclassofclaims,andtheinfluenceofthe
4SeegenerallyGeorgeCasella,AnIntroductiontoEmpiricalBayesDataAnalysis,39(2)J.OFTHEAM.STATIST.ASS’N83(1985);BradleyEfron&CarlMorris,DataAnalysisUsingStein’sEstimatorandItsGeneralizations,70J.OFTHEAM.STATIST.ASS’N311(1975);WillardJames&CharlesStein,EstimationwithQuadraticLoss,1PROCEEDINGSOFTHEFOURTHBERKELEYSYMPOSIUM361(1961).
116
informationderivedfromanindividualclaimentirelydeterminestheawardforeachclaim
inthesamplegroup,andtheinfluenceoftheinformationderivedfromsampledclaims
(ratherthananindividualclaim)entirelydeterminestheawardforeachclaiminthe
extrapolationgroup.
Ourobjectivesinthisarticlearetoexaminetheconditionsunderwhichshrinkage
canincreasetheaccuracyofdamageawardsintheclassactionandindividual-claim
contexts,andtoapplyshrinkagetogainadeeperunderstandingofthebenefitsand
limitationsoftheforegoingmethodswithrespecttoaccuracy.
WebegininSection2byreviewingthesamplingframeworkdevelopedin
AggregatingforAccuracy.InSection3,webuildonthisframeworktoexaminethebenefits
ofshrinkageintheclassactioncontext,andtoreexaminethebenefitsofsamplinginlight
ofshrinkageestimation.Weconsideralternativemethodologiesundervarious
assumptionsregardingcostandlegalconstraints.InSection4,weexamineconditions
underwhichshrinkagecanbeusedtoincreasetheaccuracyofdamageawardsinthe
individual-claimcontext.Inparticular,weconsidershrinkageinthecontextofproviding
jurorswithprior-awardinformationasguidanceindeterminingawardsforpainand
sufferingandpunitivedamages,andwederiveandillustratetheconditionsunderwhich
suchguidancecaninfactimproveaccuracy.InSection5,weconclude.
2. AFrameworkforExaminingSamplingandAccuracyinClassAction
Litigation
Inthissection,wesummarizetheframeworkdevelopedinAggregatingforAccuracy
andanumberofcentralresultsrelatedtotheuseofsamplingtoimproveaccuracyinclass
117
actionlitigation—firstinthecontextofahomogeneousclass,andtheninthecontextofa
heterogeneousclass.
2.1 SamplinginaClassofHomogeneousClaims
AggregatingforAccuracydevelopsaframeworkforexaminingtheeffectofsampling
onaccuracyinclassactionlitigation.Thearticleexaminesaprocedureinwhich1)a
numberofclaimsaresampledfromaclassofclaimsforindividualizedadjudication(and
receiptofindividualizeddamageawards),and2)themeanoftheawardsadjudicatedinthe
samplegroupisappliedastheawardforallremainingclaims,theclaimsinthe
extrapolationgroup.
Thearticle’sanalysisisintendedtorespondtoargumentsthatsuchprocedures
increaseefficiency(byallowingtheclaimantstoproceedasaclassratherthanas
individualclaimants),butonlyatthecostofreducingreliability.Itbuildsonassertionsput
forthbyProfessorsSaksandBlanckina1992StanfordLawReviewarticletoarguethat,
undercertainconditions,samplingandextrapolationmethodscanincreasereliabilityby
reducingerrorassociatedwithjudgmentvariability—uncertaintyresultingfromvariability
inthecompositionofajury,thepresentationofevidence,theselectionofajudge,etc.5
Toillustrate,considerhowreplicationmaybeusedtoreducejudgmentvariability:
[I]magine now a (costly) hypothetical procedure in which each and everyclaim[inagivenclass]werelitigatedtentimesindependently,andinwhichtheoutcomeassociatedwitheachclaimwerecomputedbytakingtheaverageofthetenverdictsassociatedwiththatclaim.Thatis,startbytakingthefirstclaimandlitigateitbeforetenindependentjuriestoobtaintenindependent
5SeeAggregatingforAccuracyat67-69;Michael.J.SaksandPeter.D.Blanck,JusticeImproved:TheUnrecognizedBenefitsofAggregationandSamplingintheTrialofMassTorts,44StanfordLawReview815,815-19(1992)[hereinafterJusticeImproved].
118
verdicts.Thenassigntheaverageofthetenverdictsastheoutcomeofthefirstcase.Byapplyingthisaggregatedoutcome,ratherthananysingleverdict,wemayreducetheerrorresultingfromjudgmentvariabilitytonearlynothing.6
AggregatingforAccuracyshowsthatsamplinginthecontextofaclassof
homogeneousclaims,throughitsimplicitorexplicituseofreplication,reducesjudgment
variabilityandtherebytoincreasesaccuracy.7Inparticular,thearticleconcludesthatgiven
aclassofNhomogeneousclaims,andlegalrestrictionsthatcanbedescribedby“reductive
sampling”—thatis,conditionsunderwhichthecourtwillnotreplaceanindividually
adjudicatedawardwithanawardextrapolatedfromotherclaims—accuracyismaximized
byrandomlyselectingasampleof𝑛∗ = 𝑁claimsforindividualizedadjudication,
assigningtheindividualizedawardsastheoutcomesoftheclaimsinthesamplegroup,
respectively,andthenapplyingthesamplemeanofthesample-groupawardsasthe
outcomeofallremaining(𝑁 − 𝑁)claimsintheclass.8
Tobemoreprecise:AssumewehaveaclassofNhomogeneousclaimsfromwhich
wesamplenclaims.Letusdefinea“correct”outcomeassociatedwithagivenclaimasthe
averageawardthatwouldemergefromrepeatedlitigationundervariouscircumstances,
suchasvariousjurycombinations,variouslawyers,judges,andpresentationsofevidence.9
The“correct”outcomecanbedefinedusingvariousmeasuresofcentraltendency,suchas
themeanormedian.Throughoutthepaper,weadoptthemeasureusedinAggregatingfor
6SeeAggregatingforAccuracyat77.
7Seeidat§4;JusticeImprovedat815-19.
8AggregatingforAccuracyat§4.
9AggregatingforAccuracyat§3;JusticeImprovedat833-34.
119
AccuracyandJusticeImproved—themean.Thus,letµbethecorrectawardineachoftheN
homogeneousclaims—themeanoftheawardsoverrepeatedlitigationofany(orall,since
theclaimsarehomogeneous)oftheNclaims.Andlet𝑋" bearandomvariabledefinedby
theadjudicatedawardintheithclaim,fori=1,2,3,...,n,wheretheXiareindependentand
identicallydistributed(i.i.d.)withmeanµandvarianceσ2,andthemeanoftheXi,fori=
1,2,3,...,n,isdefinedasXn,whichisdistributedwithmeanµandvariance,-
+.Thatis:
𝑋"~(𝜇, 𝜎))and𝑋+~(𝜇,,-
+).10Note,inAggregatingforAccuracy,itisassumedthattheXiare
distributednormally;butthisdistributionalassumptionisnotnecessaryfortheresults
derivedinthatpaperorinthecurrentpaper.Wethereforedropthenormalityassumption.
Thus,usingthesumofsquareresiduals
asthecriterionformeasuringerrorassociatedwithallNclaims,AggregatingforAccuracy
concludesthattotalerror,or“risk”—definedastheexpectationofRabove—isminimized,
andaccuracyismaximized,notbylitigatingeachclaimindividually(aprocedureoften
viewedbycourtsandscholarsastheideal,withrespecttoaccuracy),butratherby
samplingandindividuallyadjudicating
𝑁nop∗ = 𝑁
10AggregatingforAccuracyat§4.
120
claims,andapplyingthesamplemean𝑋+∗ astheoutcomeinallremaining(𝑁 − 𝑁)
claims,theclaimsinextrapolationgroup.11
Thus,inthecontextofahomogeneousclassofclaims,samplingmayimprove
accuracyaswellasefficiency.But,asexplainedinAggregatingforAccuracy,homogeneityis
notnecessaryforsamplingtoincreaseaccuracy.First,acourtmaystratifyaheterogeneous
classintomultiplerelativelyhomogeneoussubclasses.Forexample,theDistrictCourtfor
theEasternDistrictofTexas,inCiminov.Raymark,12usedsuchaprocedurewhenitdivided
aheterogeneousclassofasbestosclaimsintofivediseasecategories.Second,although
homogeneityishelpful,itisnotrequired—theerror-reducingbenefitsofsamplingapply
eventoaclassofheterogeneousclaims.
2.2 SamplinginaClassofHeterogeneousClaims
Homogeneityallowsthecourttorealizemaximalaccuracybysampling 𝑁claims.
Asaclassbecomesmoreheterogeneous,theutilityofthesamplingisreduced,sincethe
benefitsofreducingjudgmentvariabilitymustnowbebalancedwiththeerrorintroduced
byapplyingasinglepointestimate—thesamplemean—toaclassofheterogeneousclaims.
Thatis,thebenefitwithrespecttojudgmentvariabilitymustbebalancedwiththecost
withrespecttoclaimvariability.Thus,underconditionsofheterogeneousclaims,the
optimalsamplesizewillfallbetween 𝑁andN.13Simplystated,extrapolatingoutcomesof
11Id.
12751F.Supp.649(E.D.Tex.1990).
13AggregatingforAccuracyat§4.
121
unsampledclaimscanincreaseaccuracysolongastheheterogeneityoftheclaimsisnot
toolarge.
AggregatingforAccuracymodelsheterogeneousawardsasdrawsfromanormal
distributionwithmeansµiandvarianceσ2.Thatis,contrarytoahomogeneousclass,where
allclaimshavethesamecorrectawardµ,inaheterogeneousclass,eachclaimihasa
correctawardµi.Thus,Xi∼(µi,σ2),independent,whereµi∼(µ0,τ2),i.i.d.Note,hereagain
werelaxthenormalityassumptionusedinAggregatingforAccuracy.
Thus,againusingthesumofsquareresiduals,wehave
𝑅 = (𝑋" − 𝜇"))+
"23
+ 𝑋+ − 𝜇F)
8
F2+G3
asthecriterionformeasuringtheerrorassociatedwithallNclaims.Aggregatingfor
Accuracyminimizestheexpectationofthisexpression,andderivestheoptimalsamplesize
underconditionsofheterogeneousclaimstobe
.
Thus,whenτ2,theclaimvariability,isdominatedbyσ2,thejudgmentvariability,n∗falls
between 𝑁andN.Iftheclaimvariabilityisgreaterthanjudgmentvariability(τ2≥𝜎)),
thenn∗=N.Andwhentheclaimvariabilityiszero(τ2=0),then𝑛∗ = 𝑁,theresult
obtainedforahomogeneousclass.14
14Id.
122
3. ShrinkageintheClassActionContext
Thebestaggregationmethod,withrespecttoaccuracy,shouldbeconsideredin
lightofrelevantlegalandcostconstraints.Asindicatedearlier,theframeworkand
conclusionsdescribedaboveassumethatacourtmaynotreplaceanadjudicatedaward
withanextrapolatedaward(anassumptionreferredtoinAggregatingforAccuracyas
“reductivesampling”).AggregatingforAccuracyarguesthat,whilethereisclearprecedent
foraggregationandextrapolation,replacingindividuallyadjudicatedawardswith
extrapolatedawardsislikelyviolativeoftheConstitutionaswellasrulesandnormsofcivil
procedure.Intheabsenceofthisconstraint,however,otheraggregationmethodsmaybe
morebeneficialwithrespecttoaccuracy.Forexample,assumingnolegalorcost
constraints,acourtmayadjudicateallclaimsindividuallyandthenreplaceallindividual
awardswithextrapolatedawards,suchaswiththemeanoftheindividualawards.
Inthecurrentsection,werelaxthelegalconstraintspresumedinAggregatingfor
Accuracyinordertoconsidertheeffectofshrinkage—whichinvolvesthereplacementof
anadjudicatedawardwithonethatisinfluencedbyawardsincomparableclaims—on
accuracyintheclassactioncontext.Relaxingtheseconstraintsisusefulforatleasttwo
reasons.First,theremaybecontextsinwhichsuchproceduresarepermissible.For
example,partiesmayoptforsuchproceduresinsettlementormediationcontexts.Second,
examiningtheeffectsofshrinkageallowsamorecompleteunderstandingofaggregationin
lightofrelevantlegalandcostconstraints.
Thus,inthecurrentsection,webeginbyshowingthat,inthecontextofaclassof
claims,shrinkageachievesgreateraccuracythanclassicalcase-by-caseadjudication.Our
123
pointofcomparisoniscase-by-caseadjudication(asinAggregatingforAccuracy),rather
thanatypicalrepresentativeaction,becausetheformerisoftenviewedastheideal,with
respecttoreliability,andisusedastheprimaryalternativetoclasscertificationifputative
classrepresentativesareunabletoshowthatclasstreatmentisappropriate.Wethen
reexaminethesamplingresultsderivedinAggregatingforAccuracyusingshrinkage,and
showthatrelaxingthereductivesamplingconstraintandapplyingshrinkageleadsto
greateraccuracythaneventhesamplingprocedureexaminedinthatpaper.
3.1 ComparisontoIndividualizedAdjudication
Ourobjectiveinthissectionistoshowthat,givenaclassofclaims,replacingan
adjudicateddamagesawardwithanawardbasedonshrinkageincreasesaccuracy,in
expectation,foreachadjudicatedclaim(and,therefore,intheaggregate,overallsampled
claims).
Asabove,assumewehaveaclassofNclaimsandthateachclaimiisassociatedwith
acorrectawardµi,fori=1,2,3,...,N.Assumetheµi’sareequal(homogeneous)orthatthey
arisefromacommondistributionwithmeanµ0andvarianceτ2.Denotetheawardsofthen
sampledclaimsbyX1,...,Xn,andassumethattheyaredistributedaroundtheircorrect
awardsµi,respectively,withvarianceσ2.Thus,Xi∼(µi,σ2),independent,whereµi∼(µ0,τ2),
i.i.d.,andσ2andτ2areknownandrepresentjudgmentvariabilityandclaimvariability,
respectively.(SeeAggregatingforAccuracyforadiscussionregardingparameter
estimation).Asabove,wedonotrelyondistributionalassumptions.Ourobjectiveisto
imputeallofthemissingoutcomes ,whicharenotdirectlyobservable,using
124
estimatedvalues ,andtodosoinawaythatminimizeserror,representedbythe
(standard)riskfunction,
𝑅 = 𝐸 𝜇" − 𝜇" )8
"23
= 𝐸 𝜇" − 𝜇" )+
"23
+ 𝐸 𝜇" − 𝜇" )8
"2+G3
Wethusreplacetheclassicalestimator—anadjudicatedaward(Xi)—witha
shrinkageestimator(𝜇"),whichcombinestheadjudicatedawardwithadditional
informationobtainedfromtheotherclaimsintheclass,andtherebygeneratesamore
accurateaward.Wedefinetheshrinkageestimatoras:
.
Thisestimator(𝜇"U)forthecorrectoutcomeintheithclaimthusdiffersfromthe
classicalestimator,theadjudicatedaward(Xi),inthat𝜇"Uisaweightedaverageofthe
adjudicatedaward(Xi)andthemean(µ0)oftheµi,weightedbytheinverseofthe
variabilityofeach,respectively.Thus,Xiandµiareweightedbytheir“information”—the
inverseofthejudgmentvariability(σ2)andtheinverseoftheclaimvariability(τ2),
respectively.Intuitively,smallervariabilityimpliesgreaterinformation,andtherefore
heavierweight.15
Note,ifweassumethatthedistributionsofXiandµiareGaussian(or“Normal”)—
i.e.,ifweregardXi∼N(µi,σ2)asthelikelihoodandµi∼N(µ0,τ2)astheprior—weindeed
haveanexplicitstatisticaljustificationforthisestimator.ItistheBayesestimator,whichis
admissible.Itisalsothemaximumlikelihoodestimatorinthehierarchicalmodel.
15SeeCasella,supranote4.
125
Itfollowsthattheriskoftheshrinkageestimatoris
, (1)
whichissmallerthan𝑅"q :=E(Xi−µi)2=σ2,theriskassociatedwiththeclassicalestimatorXi
ofµi.
Therefore,foreachindividualclaim,assigningtheshrinkageestimatorasthe
damagesaward,onaverage,yieldsgreateraccuracy—thatis,lowerrisk—ascomparedto
theadjudicatedaward.Further,thisresultleadstotheconclusionthatapplyingthe
individualizedshrinkageaward𝜇"Utoeachclaimintheclassreducestotalrisk,sinceriskis
reducedwithrespecttoeachindividualclaim.
Now,ingeneral,wewillnotknowthevalueofµ0.Thus,substitutingitwiththe
unbiasedestimator𝜇r = 𝑋"/𝑛+"23 for𝜇rintheshrinkageestimator,wehavethe
“empirical”shrinkageestimator
, (2)
where𝜇r~(𝜇r,,-GJ-
+).NotethatintheGaussiancasewheretheXiareindependentandhave
distributionN(µi,σ2),andµihaspriordistributionN(µ0,τ2),thisestimatoriscalledthe
empiricalBayesestimator,16wherewereplacethehyperparameterµ0withitsmaximum
likelihoodestimate.ThisempiricalBayesestimator,whichconvergestotheBayes
16BradleyEfron&CarlMorris,Stein’sEstimationRuleandItsCompetitors—AnEmpiricalBayesApproach,68J.OFTHEAM.STATIST.ASS’N117(1973);HerbertRobbins,AnEmpiricalBayesApproachtoStatistics,1PROCEEDINGSOFTHETHIRDBERKELEYSYMPOSIUMMATHEMATICALSTATISTICSANDPROBABILITY157(1955).
126
estimatorasn→∞,isasymptoticallyadmissible.Therefore,statisticallyitisajustified
estimator.
Thus,letusconfirmthattheriskassociatedwiththisestimatorislessthantherisk
associatedwiththeclassicalestimator,anadjudicatedaward.Letting
𝐴 = ,u-
,u-GJu-,
wecanwritethis“empirical”shrinkageestimator𝜇" as𝜇" =AXi+(1−A)𝜇r.Theriskofthis
estimatoris
(3)
. (5)
ThisriskissomewhatlargerthanRiswithRise−Ris=n−1σ4/(σ2+τ2)>0.Intuitively,
sincewehavelessinformation—wedonotknowthetruevalueofµ0—wehavegreater
risk.However,asthesamplesizeincreases,thisriskconvergestothecaseinwhichwe
knowthetrueµ0.Thatis,Rise→Risasn→∞.
Importantly,however,althoughRise>Ris,Rise(theriskassociatedwiththeempirical
shrinkageestimator)issignificantlysmallerthanRic,theriskassociatedwiththeclassical
estimator(theadjudicatedaward).Thatis,Rise−Ric=(−1+n−1)σ4/(σ2+τ2)<0.Thus,under
thespecifiedcriterion,theempiricalshrinkageestimatorisalso(inadditiontothe
shrinkageestimator)abetterestimatorthananadjudicateaward.
127
Notethatifwedonothaveawayofestimatingclaimvariability(apossibility
discussedinAggregatingforAccuracy),wecanneverthelessrelyonStein’sestimator,17
whichdoesnotdependonclaimvariability:
,
where isanunbiasedestimatorfor(n−1)(σ2+τ2).IntheGaussiancase
(whereXiandµiareGaussian),(n−3)/Sisanunbiasedestimatorfor(σ2+τ2)−1.Therisk
associatedwithStein’sestimatorcanbederivedunderGaussianassumptions;18anditcan
beshownthatthisriskislessthantheriskassociatedwiththeclassicalestimatoraswell.
Indeed,Stein’sestimatorwillconvergetotheshrinkageestimatorasn→∞;andtherisk
associatedwithStein’sestimatorandtheshrinkageestimatorabovewillbeasymptotically
equal.
3.2 SamplingwithShrinkageEstimation
Inthissubsection,wereexaminetheaccuracybenefitsofsampling,butnowusing
theempiricalshrinkageestimator(𝜇"),ratherthananadjudicatedaward(Xi),fortheclaims
inthesamplegroup,and,onceagain,extrapolatingawardsfortheremainingclaims(the
claimsintheextrapolationgroup)usingtheestimatedglobalmean𝜇r.
Letusbeginbyderivingtheriskassociatedwiththeempiricalshrinkageestimator
inthecontextofthesamplingframeworkdiscussedabove.Thetotalriskforsampledand
non-sampledclaimsis:
17Efron&Morris,supranote4;James&Charles,supranote4.
18Efron&Morris,supranote4.
128
,
whereRise(Equation5)istheriskassociatedwithasinglesampledclaimiusingthe
empiricalshrinkageestimator(Equation2).
WecanthusseethattheriskRSisamonotonedecreasingfunctionofn:
. (6)
Thismeansthattheriskwillcontinuetodecreaseasweincreasethesamplesizen.
Ontheotherhand,ifweusetheclassicalestimator,anadjudicatedawardXi,to
estimateµi,weobtaintheriskfunction,
which,asderivedinAggregatingforAccuracyandreviewedabove,isminimizedat
. (7)
Thedivergenceoftheriskoftheempiricalshrinkageestimatorfromthatofthe
classicalestimatorisshowninFigureIV.1.FigureIV.1plotstheriskassociatedwithaclass
of1000claimsagainstthenumberofclaims,n,sampledforindividualadjudication.The
figureshowstheriskRCassociatedwiththeclassicalestimator(adjudicatedawards)and
theriskRSassociatedwiththeshrinkageestimatorforsamplesizesbetween10and200.
129
AsFigureIV.1illustrates,RCisminimizedpursuanttoequation7—wherehere,n∗is
approximately33(withσ/τ=5)—whereasRSismonotonicallydecreasinginn.AsFigure
IV.1suggests,ifwerelaxthereductivesamplingconstraintinAggregatingforAccuracy,and
insteadassumethepermissibilityofshrinkageestimation,thesamplesizethatminimizes
riskisfoundtobeN,thetotalnumberofclaimsintheclass.
(Note,ifclaimvariabilityisunknown,thecourtcanfirstsampleasmallnumberof
claimsforadjudicationanduse toestimate(n−1)(σ2+τ2).19Inthiscase,
.Wecanthenobtaintheasymptoticintervalforthisnewestimated
numberofclaimsusingthecentrallimittheoremandthedeltamethod.Wecantherefore
obtainarangefortheoptimalsamplesize,anddetermineourchoicebasedonsome
extraneouscriteria.)
19SeegenerallyAggregatingforAccuracy§§4-5.
130
NumberofSamples
FigureIV.1:Illustrationofrisk,plottedagainstthenumberofclaims,n,sampledfor
adjudication,comparingtherisk,RC,associatedwiththeclassicalestimator(adjudicated
awards),andrisk,RS,associatedwiththeshrinkageestimator,givenaclassof1000claims
andsamplesizesbetween10and200.
Importantly,theforegoingresultsshouldnotbeinterpretedassupportingan
argumentagainstsampling;thereliabilitybenefitsofsamplingareclearandsignificant
undertheconditions,includingthelegalconstraints,describedinAggregatingforAccuracy.
Rather,theseresultsdemonstratethebenefitsofshrinkage.Indeed,shrinkagedoesnot
detractfromthereliabilitybenefitsofsampling;rather,itsufficientlyenhancesthe
accuracyofindividualestimates—i.e.,resultingfromindividualizedadjudicationandthe
replacementofindividuallyadjudicatedawardswithshrinkageestimates—that,inasense,
itreducestheneedfor(i.e.,therelativebenefitsof)sampling.
50 100 150 200
Risk of 1000 claims
R C
R S
n * = 33
131
Furthermore,itissignificantthatincasesinwhichjudgmentvariabilitydominates
claimvariability(σ2>τ2),shrinkageestimationreducesriskatahighratewhenn<n∗and
atarelativelylowratewhenn>n∗(since,asnapproachesN,thesecondtermontheright
handsideofequation6approaches0,andthefirsttermdominates).Therefore,ifthe
reductivesamplingconstraintisrelaxed—and,inparticular,ifcourtsarewillingtoadjust
individualadjudicationstoincorporateaggregateinformation—then,tobalanceconcerns
foraccuracywithconcernsforlitigationcosts,acourtmayconstructasampling-basedtrial
planpursuanttotheresultsderivedinAggregatingforAccuracy,butaddtheadditional
stepofreplacingtheadjudicatedawardsofsampledclaimswithshrinkageestimates.That
is,thecourtmaysample
claimsforindividualizedadjudication;assignindividualizedshrinkageestimatestothen∗
sample-groupclaims(basedontheirrespectiveindividualizedawardsaswellasthemean
ofthesampledclaims);andapplythemeanoftheawardsinthesamplegroupasthe
outcomeofallnon-sampledclaims.Thisprocedureisidenticaltotheprocedurederivedin
AggregatingforAccuracy,withonedifference:here,thecourtwouldapplyindividualized
shrinkageestimates,ratherthanindividualizedclassicalawards,astheoutcomesofthe
claimsinthesamplegroup.
Inconcludingthissection,wenotethatwedonotintendtomakenormative
statementsregardingtheappropriateuseofshrinkageinlitigation.Forexample,itis
beyondthescopeofthispapertoaddresstheconstitutionalityofshrinkageorrelated
policyconcerns.Instead,wesimplyintendtodevelopamorecompleteunderstandingof
132
aggregation,withrespecttoreliability,andtoexamineanumberofkeyresultsregarding
thereliabilitybenefitsofshrinkage.
Givenourresultsabove,choosingtheaggregationapproachtomaximizeaccuracy
dependsontheapplicablelegalandcostconstraints.Forexample,ifthereisnoconcernfor
thereductivesamplingconstraintorcostconstraints,repeatedadjudicationsofeachclaim
inaclasscanleadtothegreatestdegreeofaccuracy.Ifthereisconcernforlitigationcosts
butnoconcernforthereductivesamplingconstraint,samplingaproportionofclaims
pursuanttoAggregatingforAccuracyandreplacingtheadjudicatedawardsinthesample
groupwithshrinkageestimates(andstillusingthemeanofthesamplegroupto
extrapolateawardsforallremainingclaims)maymaximizeaccuracy,giventheapplicable
costconstraints.Finally,ifthereisconcernforlegalconstraintsdescribedbyreductive
sampling(whetherornotthereisalsoconcernforlitigationcosts),thesamplingprocedure
(withoutshrinkage)derivedinAggregatingforAccuracyisthealternativethatmaximizes
accuracy.
Inthefollowingsection,weextendourdiscussiontocircumstancesoutsideofthe
classactioncontext.Inparticular,weconsiderthereliabilityimplicationsofshrinkagein
theindividualclaimcontext,whereinsteadofshrinkingtowardtheestimatedglobalmean
ofadefinedclassofclaims,weshrinktowardtheestimatedglobalmeanofapopulationof
awardsinpriorcomparablecases.
4. ShrinkageEstimationintheIndividual-ClaimContext
InSection3,wederivedthepotentialaccuracybenefitsofreplacinganadjudicated
awardwithashrinkageawardinthecontextofaclassof(homogeneousorheterogeneous)
133
claims.Weshowedthatshrinkagemaybebeneficialevenunderconditionsofhighclaim
variability.Theclassactioncontextprovidesaconvenientstartingpointfortheapplication
ofshrinkage,andaggregationproceduresgenerally,sincewearegivenapopulationof
claims(presumablywithrelativelylowclaimvariability)overwhichwearetoaggregate.
However,aheterogeneousclassofclaimsboundtogetherbysomecommonthreadshould
notbeunderstoodasfardifferent,forpurposesofshrinkage,fromapopulationofprior
claimsthataresimilarlyboundtogetherbysomecommonthread.Therefore,inthecurrent
section,weextendourdiscussionofshrinkagetotheindividual-claimcontext.
Forpurposesofthissection,therearetwomajorchallengestoapplyingshrinkagein
theindividual-claimcontext.Thefirstistheproblem,highlightedaboveinourdiscussionof
reductivesampling,thatgenerallyacourtcannotlegallyreplaceanadjudicateddamages
awardwithanawardextrapolatedformulaically.Thesecondistheproblemofidentifyinga
suitablesetofpriorcomparablecasestobeusedforshrinkage.
Itisbeyondthescopeofthecurrentpapertoexaminethelegalityofreplacingan
adjudicatedawardwithashrinkageaward.Rather,wecouchourdiscussionofshrinkage
hereinthecontextofarecentarticle,writtenbyoneoftheauthors,examiningprocedures
thataimtoreducethejudgmentvariabilityofcertaintypesof(particularlyunpredictable)
damageawardsbyprovidingafact-finder,priortoitsdeterminationoftheaward,with
informationregardingawardsinpriorcomparablecases.20Inparticular,TheLogicofCCG
usesprinciplesofshrinkagetoexplaintheaccuracybenefitsofcomparable-caseguidance,
20TheLogicofCCGat§1.
134
beyondtheempiricalresultthatsuchguidancereducesvariability,andtoaddressa
numberofmajorchallengestosuchmethods.Providingafact-finderwithprior-award
informationmayserveasaninnovativewayofusingshrinkagetoimprovecertaintypesof
damageawards—afterall,itenablesafact-findertoincorporatepriorawardinformation
justasashrinkageestimatorwould.Themajordifferenceisthatashrinkageestimator
incorporatessuchinformationformulaically,whereas,withthemethodsexaminedinThe
LogicofCCG,wemustrelyoncertainbehavioralassumptions.
Asdescribedinthatpaper,thereissubstantialevidencethatprovidingjurorswith
suchinformationiseffectiveinreducingjudgmentvariabilityandinfluencingadamages
awardgenerally,butwhetherajurorcanbesaidtoactasashrinkageestimator(e.g.,
allowingprior-awardinformationtoinfluencetheawardinproportiontotheinverse
variabilityofsuchinformation)iscurrentlybeingstudiedinaseriesofrandomized
experiments.
Inthecurrentsection,weaddressthesecondchallenge—theproblemofidentifying
asetofpriorcomparablecases.Effectively,weassumethatthefactfinderinTheLogicof
CCGactsasashrinkageestimator,andweexaminetherobustnessofcomparable-case
guidance,withrespecttoaccuracy,tovariationsinthesetofpriorcomparablecases
identified.Inotherwords,ourconcernisthis:assumingthefact-finderacts“rationally,”in
thesenseofoptimallyusingprior-awardinformationasashrinkageestimatorwould,what
choicesofpriorcases(fromwhichprior-awardinformationisobtained)willincrease
accuracyinexpectation?Forexample,how“wrong”canasetofpriorawardsbebefore
135
prior-awardinformationreducesaccuracy?Thesequestionsareessentialfordetermining
policysurroundingsuchmethods.
Althoughwedonotknow,atthispoint,whetherjuriesactaspredicted,applying
shrinkageexplicitlytothiscontextenablesanunderstandingofthepotentialbenefits,and
someofthepotentialrisks,associatedwiththeuseofcomparable-caseguidance.Atthe
veryleast,ouranalysisenablesanunderstandingofthepotentialbenefitsofcomparable-
caseguidance,andtherobustnessofthesebenefitsto“incorrect”setsofpriorawards.
4.1 Background:TheUseofComparable-CaseGuidancetoReduceAward
Variability
TheproblemaddressedinTheLogicofCCGistheunpredictability(i.e.,judgement
variability)ofawardsforpainandsufferingandpunitivedamages—twotypesofawards
forwhichthejuryreceivesverylittleguidanceindeterminingtheaward.TheSupreme
Courtandlowercourtshaverepeatedlyexpressedtheimportanceofreducingthe
variabilityofsuchawards.21
Thepaperhighlightstheproblemswithrelyingonexistingmethods,suchasadditur
andremittitur,toolsusedbycourtstoincreaseordecreasetheamountofanawardfound
tobeinadequateorexcessive.Althoughthesetoolscanbeuseful,andcanbeusedto
incorporateprior-awardinformationinvariousways,22andinconjunctionwithother
methods,alonetheyaddressextremeawardsonly,ratherthanvariabilitygenerally,and(in
21TheLogicofCCGat§2.See,e.g.,ExxonShippingCo.v.Baker,554U.S.471(2008).
22SeegenerallyJosephB.Kadane,CalculatingRemittiturs,8LAW,PROBABILITY&RISK125(2009).
136
practice)theyordinarilyaddressonlyexcessiveawards,ratherthaninadequateones.23
Additionally,widespreaduseofsuchmethodsarguablyreplacesthefact-finder’sdiscretion
withthatofthecourt,raisingconstitutionalandpolicyissues.Othermethods,suchascaps,
arbitrarilydrawcutoffpoints,leadingtosubstantialbiasandperverseoutcomes.24
Asmentionedabove,thereisempiricalevidencethatprovidingthefactfinderwith
informationregardingawardsinpriorcasesiseffectiveinreducingvariability.Butsuch
studiesdonotaddresstheeffectofprior-awardinformationonaccuracy—thatis,biasand
variability.
TheLogicofCCGestablishesaframeworkforexaminingthebenefitsandlimitations
ofprior-awardinformationintermsofaccuracy;anditaddressesanumberofmajor
challengestotheuseofprior-awardinformationtoreducevariability,includingthe
possibilityofusingawardinformationfroman“incorrect”setofcases.25Inthecurrent
section,inapplyingshrinkageestimationtotheindividualclaimcontext,weanalyze,and
deriveanumberofsignificantresultsregarding,thislatterchallengeinparticular.
4.2 IdentifyingPriorCases
Asapreliminarymatter,itisimportanttorealizethatthereisno“correct”or
“incorrect”setofpriorcases.AsdiscussedinTheLogicofCCG,theeffectofprior-award
informationonaccuracydependson1)thealignmentofmaterialfactsandissuesinthe
subjectcasetothoseinpriorcases;2)thesubstantivebreadthofthepriorcases;and3)the
23TheLogicofCCG§3.
24Id.
25SeeId.at§1.
137
numberofpriorcases—orthe“samplesize.”Forexample,thealignmentoffactsandissues
affectsthebiasintroducedbythepriorawards—wewouldlikefortheaveragecorrect
awardinthepriorcasestoalignwiththecorrectawardinthesubjectcase.Thebreadthof
thepriorawardsaffects,e.g.,theinfluenceoftheprior-awardinformationonthesubject
award;butasetofpriorcasesthatcontainsonlyidentical,oralmostidentical,material
factsandissuesmayresultinasamplesizeofoneortwo,orevenzero,priorawards.Thus,
inidentifyingasetofpriorcases,acourtmustbalanceitsinterestsinmaintaininga
reasonablesamplesize,areasonablebreadth,andcasesthatinvolvefactsandissuesthat
arerelativelyalignedwiththoseinthesubjectcase.26
ConsidertheexampleoftheSeventhCircuitcase,Jutzi-Johnsonv.UnitedStates,27
describedinTheLogicofCCG,involvinganawardforpainandsufferingarisingfrom
circumstancesinwhichajailinmatecommittedsuicidebyhanging,duetoafailureofthe
jailtosupervisehimappropriately.Acourtconsideringpriorawards(asJudgePosnerof
theSeventhCircuitdid)mightconsiderwhethertouseonlycasesinvolvinginmateswho
hungthemselves,peoplewhohungthemselvesfromthegeneralpopulation,peoplewho
committedsuicidefromthegeneralpopulation,peoplewhosufferedfromasphyxiation
(e.g.,drowning)fromthegeneralpopulation,etc.28Ifthecourtrestrictsitsconsiderationto
casesinvolvinginmateswhohungthemselves,itmayobtainonlyatinysamplesize;ifthe
26Id.at§§4-5.
27263F.3d753(7thCir.2001).
28Seeid.at760-61.
138
courtusesawiderbreadthofcases,thepriorawardswillhavelessinfluence,andhigher
riskofintroducingbias.29
Foramoredetaileddiscussionoftheseconsiderations,seeTheLogicofCCG.The
importantpoint,forpurposesofthecurrentanalysis,isthattherearetradeoffsbetween
breadth,alignment,andsamplesize—combinationsofwhichcorrespondtovariouslevels
ofbiasandvariance,andthereforeaccuracy.Thepurposeofthecurrentanalysisisto
examinetheseeffectstounderstandtheconditionsunderwhichprior-awardinformation
increasesaccuracy.
Thus,assumethatwehaveanindividualclaimthatreceivesawardY.Yiscentered
atthecorrectawardµywithjudgementvariabilityσy2(assumedtobeknown).Thecorrect
awardµy,iscenteredatλ0withvariance .Thatis,thecorrectawardcanbeunderstoodas
asingleawardfromadistributioncontainingapopulationofawardsfromcomparable
claims.Thecorrectawardsofthecomparableclaims,aswellasthatofthesubjectclaim,
aredistributedaroundaglobalmeanλ0withvariability .Thus,
.
Tobeclear,instatisticalterms,by“comparable”claimsorcases,wemeantosuggest
thattheirawardssomehowarisefromthesameglobalmean.
Now,ifweknowtheglobalmean(λ0)andvariability( )associatedwiththis
population,theshrinkageestimatoris
.
29TheLogicofCCGat§5.
139
SimilartoEquation1,weknowthattheriskofthisestimatoris( ,whichis
smallerthanσ2,theriskassociatedwiththeclassicalestimatorYtoestimateµy.Noticethat
thisestimatorrequiresustoknowthevaluesofλ0andη0.Amorerealisticscenarioisone
inwhichwedonotknowthesevalues,andinsteadneedtoestimatethembasedonprior
awards.AssumethattheidentifiedsetofpriorcasesinvolvesawardsX1,...,XNcenteredat
thecorrectawardsµ1,...,µNwithjudgementvariabilityσ2(assumedtobeknown).Thatis,
Wecanthenusethefollowingunbiasedestimatorstoestimateµ0and :
.
Wethereforeusethe“empirical”shrinkageestimator,
,
whichconvergestothe(non-empirical)shrinkageestimatorasN→∞.AsinSection3,
replacingλ0andη0withunbiasedestimatorsintroducessomeamountofuncertaintyinto
theestimatorandthusintroducessomerisk.However,asN→∞,theriskconvergestothat
ofthe(non-empirical)shrinkageestimator.Therefore,intermsofrisk,webenefitfroma
sufficientlylargeN,thenumberofpriorcases.Thus,ifthesetofpriorcasesistoosmall—in
thesensethattheriskresultingfromtheestimatedvaluesofλ0andη0dominatesthe
benefitsoftheempiricalshrinkageestimator—acourtcanincreasesamplesizeby
expandingthesubstantivebreadthofthepriorcases.
Inthefollowingsubsection,wediscussthebreadthandalignmentofpriorcases.
Although,forthereasonexplainedabove,samplesizeisanimportantconsiderationin
140
determiningbreadth,theaccuracybenefitsofshrinkagearefairlyrobusttolowsample
size.Specifically,becausetheshrinkageestimatorisinfluencedbysamplesizeonlythrough
theestimationofthemeanandvarianceofthedistributionofpriorawards,andbecause
thesequantitiescanbeestimatedreasonablywellwithasmallsamplesize,asampleof5to
15oftensuffices.Perhapsmostimportantly,asdiscussedindetailbelow,theaccuracy
benefitsofshrinkagearequiterobusttomisalignment;therefore,eveniftheestimation
turnsouttoberelativelypoor,shrinkagecangenerallybeexpectedtoimproveaccuracy.
Thisisespeciallytrue,inlightoftheremittiturdeviceandappellateprocess,bywhichthe
courtsmoderateextremeoutliers.Forthesereasons,althoughweremainconsciousof
samplesize,forsimplicity,itdoesnotplayacentralroleinourexamplesandillustrations
below.
4.3 BreadthandAlignmentofPriorCases
Weareinterestedinexaminingtwoconsiderations:breadthandalignment.To
illustrate,considerthecaseofJutzi-Johnson,discussedabove.JudgePosnerdisagreedwith
thepriorcasesidentifiedbyboththeplaintiffandthedefendant.Heexplainedthat“[t]he
plaintiffcitesthreecasesinwhichdamagesforpainandsufferingrangingfrom$600,000
to$1millionwereawarded,butineachonethepainandsufferingcontinuedforhours,not
minutes”;andthat“[t]hedefendantconfineditssearchforcomparablecasestoother
prisonsuicidecases,implyingthatprisonersexperiencepainandsufferingdifferentlyfrom
otherpersons,sothatitmakesmoresensetocompareJohnson’spainandsufferingtothat
ofaprisonerwhosufferedatoothachethantothatofafreepersonwhowasstrangled,and
concludingabsurdlythatanyawardforpainandsufferinginthiscasethatexceeded$5,000
141
wouldbeexcessive.”30JudgePosnerultimatelyconcludedthat“[t]hepartiesshouldhave
lookedatawardsinothercasesinvolvingasphyxiation,forexamplecasesofdrowning,
whicharenumerous.”31
Inthelanguageofthecurrentsection,JudgePosnerdisagreedwiththealignmentof
theplaintiff’scases,implyingthatawardscorrespondingtocasesinvolvinghours,rather
thanminutes,ofpainandsufferingwouldbeinappropriatelyhigh.Hedisagreedwiththe
breadth(andthealignment)ofthedefendant’scases,suggestingthatasetofcases
involvingthepainandsufferingofinmates,ratherthanthegeneralpopulation,istoo
narrow;andthatthedefendant’sfocusoninmatesledtoalignmentissuesthatresultedin
“absurd”conclusions.Additionally,JudgePosnerseemstosuggestthatthesetsofcases
identifiedbythepartiessufferedfromsmallsamplesizesaswell,indicatingthat
broadeningthepriorcasestoincludethoseinvolvingasphyxiationinthegeneral
populationwouldleadtonumerouscases.
Thus,consideracasethatreceivesanawardY,whichis“drawnfrom”adistribution
centeredatthecorrectawardµywithjudgementvariabilityσy2(known),whereµyis
centeredatλ0withvariance .Thatis,
.
AssumethatthecourtidentifiesasetofpriorcasesinvolvingawardsX1,...,XNwith
correctoutcomesµ1,...,µNcenteredatµ0withvarianceτ2.Thus,
30Jutzi-Johnson,263F.3dat760.
31Id.
142
Xi∼(µi,σ2),µi∼(µ0,τ2);i=1,...,N.
EssentiallythismeansXi∼(µ0,ψ2)for1≤i≤N,whereψ2=σ2+τ2.Now,consideran
estimatoroftheform
, (8)
whichweapproximatebyplugginginunbiasedestimators
,
fortheunknownparametersµ0andψ2=σ2+τ2,respectively,toobtain:
, (9)
Again,as .Thus,theriskofthisshrinkageestimator𝜇is
whichissmallerthanσy2when
.(10)
Letusconsiderthemeaningofthisconditionandthenexamineanumberof
numericalexamplestogainadeeperunderstandingoftheconditionsnecessaryfor
increasingaccuracy.Ontheright-handsideofEquation(10),ψ2=σ2+τ2isthetotal
variance(thesumofclaimvariabilityandjudgmentvariability)ofthepriorawards;andσy2
isthejudgmentvariabilityofthesubjectcase.Ontheleft-handsideofEquation(10),(µ0−
λ0)2isthesquareofthemisalignment(i.e.,thedifference)betweentheexpectedcorrect
143
awardinthesubjectcaseandthemeanofthepriorawards;and canbethoughtofasthe
claimvariabilityofthehypotheticalpopulationtowhichthesubjectcasebelongs.For
simplicity,wecanset =0andviewthecaseasitsownpopulation.Theconditionwould
besatisfied,forexample,if(1)thejudgmentvariabilityofthesubjectawardisgreaterthan
thehypotheticalclaimvariability(e.g.,where =0),and(2)thebreadthoftheprior
awardsisgreaterthantheirmisalignment.Ofcourse,theeffectsofonecanbeoffsetbythe
effectsoftheother.Forexample,theeffectsofextrememisalignmentcanbeoffsetbythe
effectsofextremejudgmentvariability.
Further,ingeneral,thegreaterthedispersionofthepriorawards,themore
“tolerance”thereisformisalignment.Ontheotherhand,higherprior-awardconcentration
requiresgreateralignment.Thus,itmaybebeneficialforthebreadthofthepriorawardsto
reflectthecourt’sconfidenceintheiralignmentwithrespecttothesubjectaward.
LetusconsideranexamplebasedondataobtainedinSaksetal.,32whichtestedthe
effects,withrespecttovariability,ofprovidingmockjurorswithcertaininformation
regardingpriorawards.Inonesetofcontrolconditionsinwhichmockjurorswere
providedwithafactpattern(basedonactualpersonalinjurycases)involvinga“high-
severityinjury,”abrokenback,themeanandstandarddeviationoftheawardamounts
determinedbyparticipantswasapproximately$3millionand$4million,respectively.33
Notethatthesevaluesarebasedonamountsdeterminedbymockjurorsratherthan
mockjuries.Also,however,“[b]ecausethedistributionfortherawdollarawardswas
32MichaelJ.Saksetal.,ReducingVariabilityinCivilJuryAwards,21LAWANDHUMANBEHAVIOR243(1997).
33Seeid.at249-53.
144
highlyvariableandpositivelyskewed,awardsgreaterthantwostandarddeviationsabove
themeanwererecodedtotheamountattwostandarddeviations.”34Saksetal.thereby
limitedthevariabilityofthedata.
BasedonthedatafromSaksetal.,weconstructFigureIV.2,whichassumesacorrect
award(µy)of$3millionandjudgmentvariability(σy)of$4million.Itisintuitivetoimagine
anapproximately“normal”distributionwithalmostallawardsfallingbetween0and$11
million(thatis,themean±2standarddeviations).Weassumealsothatµy=λ0=3million
andη0=0.Thatis,weviewthecaseasitsownpopulation,ratherthanadrawfroma
distributionofawards.Thus,thefigureillustratesrisk(definedhereinaserror)asa
functionofthemeanofthepriorawards(indicatingalignment).Wecansee,forexample,
thatifpriorawardsarecenteredat$4millionwithstandarddeviationequalto$2million,
wereduceriskby92%byusingtheshrinkageestimatorratherthantheclassical
estimator;andwecanexpecttheawardtofallwithintheinterval$74,000to$5.26million
(thatis,themean±2standarddeviations),ratherthan$0to$11million.Iftheprior
awardsarecenteredat$5millionwithvariability$3million,wereduceriskby76.8%,
relativetotheclassicalestimator;andwecanexpecttheawardtofallwithintheinterval$0
to$6.85million.Althoughnotshowninthefigure,itcanbecalculatedthat,forprioraward
meanandstandarddeviationequalto$8millionand$4million,respectively,wereduce
riskby36%,relativetotheclassicalestimator.Finally,ifthedistributionofpriorawards
hasameanandstandarddeviationequalto$3million(thecorrectaward)and$2million,
34Id.at249.
145
respectively,thevariability(intermsofstandarddeviation)oftheestimatoris$0.8million
ratherthan$4milliondollars;andriskisreducedby96%.
RiskofShrinkageEstimators(Black)&RiskofClassicalEstimator(Gray)
FigureIV.2:Comparisonoftheriskcorrespondingtotheshrinkageestimator(black
curves)andtheriskcorrespondingtotheclassicalestimator(grayhorizontalline)plotted
againstthemeanofthepriorawardswhenthecorrectawardis$3million(verticalblack
bar),andassumingη0=0(thesubjectcaseformsitsownpopulation)andjudgment
variabilityofthesubjectcase,σy,isequalto$4million.Theblackcurvescorrespondto
differentvaluesofprior-awardvariability,whichrangesfrom$0.2millionto$3million.
Notethat,althoughSaksetal.usedmockjurorsratherthanjuries,ourchoiceof
judgmentvariability—akeyfactorforwhetherprior-awardinformationcausesaccuracyto
increaseordecrease—islikelyconservative,sinceourchoice($4million)reflectsthe
methodologyinthatstudywherebyallawardamountsabovetwostandarddeviations
abovethemeanwerereducedtotheamountoftwostandarddeviations.Tobesafe,
Mean of prior awards (millions of dollars) 0 1 2 3 4 5 6 7
prior award variability = 0.2 prior award variability = 1 prior award variability = 2 prior award variability = 3
Risk of Classical Estimator
146
however,letusillustrateasecondexampleusinghalfthestandarddeviationusedaboveto
definejudgmentvariability.Thus,FigureIV.3assumesacorrectaward(µy)of$3million
andjudgmentvariability(σy)of$2million.Inthisexample,ifpriorawardsarecenteredat
$4millionwithastandarddeviationof$2million,wereduceriskby68.75%,relativetothe
classicalestimator.Ifthedistributionofpriorawardsiscenteredat$1millionwitha
standarddeviationof$400,000,adistributionthatisconcentratedaroundasignificantly
incorrectaward,weneverthelessreduceriskby7.5%,relativetotheclassicalestimator.
Finally,ifthedistributionofpriorawardshasameanandstandarddeviationequalto$3
million(thecorrectaward)and$2million,respectively,wereduceriskby75%,relativeto
theclassicalestimator.Furthermore,ifthevariabilityinthisfinalscenariowere$200,000,
theriskassociatedwiththeshrinkageestimatorisevensmaller—areductionof99.99%
(correspondingtoareductioninstandarddeviationfrom$4millionfortheclassical
estimatorto$20,000fortheshrinkageestimator).
147
FigureIV.3:Comparisonoftheriskcorrespondingtotheshrinkageestimator(black
curves)andtheriskcorrespondingtotheclassicalestimator(grayhorizontalline)plotted
againstthemeanofthepriorawardswhenthecorrectawardis$3million(verticalblack
bar),andassumingη0=0(thesubjectcaseformsitsownpopulation)andjudgment
variabilityofthesubjectcase,σy,isequalto$2million.Theblackcurvescorrespondto
differentvaluesofprior-awardvariability,whichrangesfrom$0.2millionto$3million.
Lastly,weconstructathirdfigureusingdatafromBovbjergetal.,35whichexamined
realawarddatabyseverityofinjurytoanalyzethevariabilityofawardsforpainand
suffering.Thedatapresentedherearearguablyveryconservativeaswell,since1)the
authorsaltogetherexcludedthe5%ofawardvaluesfarthestfromthemedian;2)thedata
includereportedincidentsofadditurandremittitur;and3)thedatareflectthevalueof
35RandallRBovbjergetal.,ValuingLifeandLimbinTort:SchedulingPainandSuffering,83NW.U.L.REV.,908(1988).
Risk of Shrinkage Estimators (black) & Risk of Classical Estimator (gray)
Mean of prior awards (millions of dollars) 0 1 2 3 4 5 6 7
prior award variability = 0.2 prior award variability = 1 prior award variability = 2 prior award variability = 3
Risk of Classical Estimator
148
dollarsin1987.36Thus,inFigureIV.4,weconsidertheexampleofseveritylevel7(outof9,
representingsevere,butnotmaximal,injuries),withmeanandstandarddeviationvalues
ofapproximately$2millionand$2million.Thegraphagaindisplaysdifferentcurves
correspondingtodifferentlevelsofprior-awardvariability.Italsoillustratestherisk
associatedwiththeclassicalestimatorasashadedhorizontalline(sincetheriskofthe
classicalestimatordoesnotdependonpriorawards)at$4millionsquared,whichisequal
tothestandarddeviationsquared.First,wecanseethatifpriorawardsarecenteredat$2
million(assumedtobethecorrectaward)withastandarddeviationof$500,000,we
reduceriskby99.65%,relativetotheclassicalestimator.Ifthepriorawardshaveamean
andstandarddeviationequalto$500,000and$500,000,wereduceriskby49.83%—a
milderreduction,duetotheintroductionofbias(butareductionnevertheless).Iftheprior
awardshaveameanandstandarddeviationequalto$500,000and$1.5million,
respectively,wereduceriskby64%—animprovementrelativetotheformerscenario,due
totheincreaseinbreadth,whichreducestheeffectofthebias.Ifthepriorawardshavea
meanandstandarddeviationequalto$4.2millionand$200,000,respectively,weincrease
riskby18.63%,sincewehaveatightlybounddistributioncenteredatasignificantly
incorrectawardvalue.
Ontheotherhand,ifthepriorawardshaveameanandstandarddeviationequalto
$4.2millionand$1.5million,wereduceriskby37.48%,since,now,theintroductionofbias
islessenedduetohighprior-awardbreadth,andthebeneficialeffectofpriorawardson
awardvariabilitydominates.
36Seeid.at919-24.
149
RiskofShrinkageEstimators(black)&RiskofClassicalEstimator(gray)
FigureIV.4:Comparisonoftheriskcorrespondingtotheshrinkageestimator(black
curves)andtheriskcorrespondingtotheclassicalestimator(grayhorizontalline)plotted
againstthemeanofthepriorawardswhenthecorrectawardis$2million(verticalblack
bar),andassumingη0=0(thesubjectcaseformsitsownpopulation)andjudgment
variabilityofthesubjectcase,σy,isequalto$2million.Theblackcurvescorrespondto
differentvaluesofprior-awardvariability,whichrangesfrom$0.2millionto$4million.
Usingthederivationsandexamplesabove,westatethefollowingconclusions:
1. Priorawardsthatarerelativelyalignedwiththecorrectawardcanleadtolargeaccuracy
benefits.
2. Higherbreadthofpriorawardsleadstoreducedinfluenceofpriorawards,andtherefore
reduced accuracy benefits—but improvements nevertheless. Considerations in
determiningappropriatebreadthalsoinclude1)confidenceinthealignmentoftheprior
awards,and2)obtaininganappropriatesamplesize.
Mean of prior awards (millions of dollars) 0 1 2 3 4 5
prior award variability = 0.2 prior award variability = 0.5 prior award variability = 1.5 prior award variability = 4
Risk of Classical Estimator
150
3. Priorawardsthataremisaligned—evensignificantlymisaligned—butareofhighbreadth
leadtoimprovements,butimprovementsthataresmallrelativetopriorawardsthatare
alignedandareoflowerbreadth.
4. Increasingonly thebreadthof theprior awards (without affectingalignment)will not
harmaccuracy,butwillonlyreducetheinfluenceofthepriorawards,andthereforetheir
benefitswithrespecttoaccuracy.
5. Priorawardsthataresignificantlymisalignedandareoflowbreadthcanleadtoharmful
effects on accuracy. However, harmful effects generally require prior awards that are
tightlyboundaroundasignificantlyincorrectaward.
Inshort,underrelativelymildconditions,theshrinkageestimatoroutperformsthe
classicalestimator,anadjudicatedaward.
5. Conclusion
Claimaggregationmethodsmayenableacourttoincreasetheaccuracyofdamage
awardsbyallowingforthesharingofinformationacrossclaims.Recentpapershave
arguedassuchinthecontextsof1)samplingaproportionofclaimsinaclassactionfor
purposesofextrapolatingawardsforunsampledclassclaims;and2)providingafact-
finderwithprior-awardinformationasguidanceindeterminingawardsforpainand
sufferingorpunitivedamages.
Ourgoalinthispaperwastoexaminecertainimplicationsofwhatcanbe
consideredathird,butcloselyrelated,formofclaimaggregationcalledshrinkage
estimation.Weanalyzedtheaccuracybenefitsofshrinkageinthecontextsofsamplingand
comparable-caseguidance;andweappliedittogainadeeperunderstandingofthebenefits
151
andlimitationsofclaimaggregationgenerally.Webeganouranalysisbyapplying
shrinkageintheclassactioncontext,andbyreexaminingtheresultsobtainedin
AggregatingforAccuracytoderivealternativemethods,withrespecttoaccuracy,under
variouslegalandcostconstraints.Wefoundthatshrinkageleadstogreateraccuracyas
comparedtoindividualadjudication,andalsoascomparedtothesamplingmethods
discussedinAggregatingforAccuracy.Butitalsorequiresrelaxingcertainlegalconstraints
thatareindeedapplicableinmanylegalcontexts.Wethereforediscussedalternatives
basedonvariouscombinationsofsuchconstraints.
Wethenextendedouranalysistotheindividualclaimcontext,applyingshrinkageto
gainadeeperunderstandingofthepotentialbenefitsandlimitationsofcomparable-case
guidance.Applyingcertainbehavioralassumptions,wederivedaformulathatexpresses
thepreciseconditions,intermsofthealignmentandbreadthofasetofpriorawards,
underwhichcomparable-caseguidanceleadstoanincreaseordecreaseinaccuracy.We
thenusedouranalysistodrawconclusionsregardingtherobustnessoftheaccuracy
benefitsofcomparable-caseguidancetovariationsinthesetofpriorawardsidentified,and
toillustrateitusinganumberoffiguresandexamples.
Shrinkageisanimportantconceptinstatistics.Althoughithas(unsurprisingly)
receivedlittleattentioninlaw,theideaofsharinginformationacrossclaimshasnumerous
applications.Ithasthepotentialtoplayasignificantroleinthelaw—atleastimplicitly,
suchaswiththeclaimaggregationmethodsdiscussed—toreduceawardvariabilityand
increasereliabilitygenerally.
152
V. GuidingJurorswithPrior-AwardInformation:ARandomized
Experiment*
(Coauthor:ReaganRose)
1. Introduction
Inciviljurytrials,juriesarefrequentlyaskedtodetermineawardsforpainand
sufferingandpunitivedamages.Buttheyreceivescantguidancetoassistthemintheir
assessments.Asaresult,thesedamageawardsarenotoriouslyvariable,underminingthe
law’sfairnessanddeterrenceobjectives,andcausingawiderangeofharmstoindustries
andindividuals.1Indeed,courtshavelongrecognizedandexpressedconcernforthis
“virtuallyunbridleddiscretion”2ofjuries,andtheneedtoaddressthis“standardless,
unguidedexerciseofdiscretionbythetrieroffact,reviewable...pursuanttonostandard
toguidethereviewingcourteither.”3
Arecentarticle,writtenbyoneoftheauthors,examinedthebenefitsofcomparable-
caseguidance(CCG),or“prior-awardinformation”—informationregardingawardsinprior
*HillelJ.Bavli&ReaganRose,GuidingJurorswithPrior-AwardInformation:ARandomizedExperiment.ThisresearchbenefitedimmenselyfromtheguidanceofProfessorDonaldRubin,andfromsupportprovidedbytheInstituteforQuantitativeSocialScienceandtheCenterforAmericanPoliticalStudies. 1SeePaynev.Jones,711F.3d85,94(2dCir.2013);seealsoExxonShippingCo.v.Baker,554U.S.471,499-503(2008).
2Geressyv.DigitalEquip.Corp.,980F.Supp.640,656(E.D.N.Y.1997)(quotingLeslieA.Rubin,ConfrontingaNewObstacletoReproductiveChoice:EncouragingtheDevelopmentofRU-486ThroughReformofProductsLiabilityLaw,18N.Y.U.REV.L.&SOC.CHANGE131,146(1990-91)).
3Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001);seeHillelJ.Bavli,TheLogicofComparable-CaseGuidanceintheDeterminationofAwardsforPainandSufferingandPunitiveDamages,U.CIN.L.REV.at5-8(forthcoming,2017)[hereinafterTheLogicofCCG].
153
comparablecasesasguidancefordeterminingdamageawards—asanapproachto
addressingtheunpredictabilityofawardsforpainandsufferingandpunitivedamages.4
ThearticleconcludedthatCCGisgenerallyeffectiveinreducingunpredictabilityand
improvingtheaccuracyofawardsforpainandsufferingandpunitivedamages.5However,
theargumentforCCGmethods—thoseproposedinTheLogicofCCGandbyprevious
commentators—relyoncertainuntestedbehavioralassumptions.
Specifically,theprimaryobjectiontoCCGmethodsisthefollowing:“ifourproblem
istheunpredictabilityofawardscausedbyafact-finder’sinabilitytoassessobjectivelythe
appropriatevalueofawardsforpainandsufferingorpunitivedamages,howisitbeneficial
toprovideafact-finderwithinformationregardingdamagesawardedinpriorcasesthat
areseparateanddistinctfromthepresentcaseandthatpresumablysufferfromthesame
arbitrarinessthatwewishtoaddressinthepresentcase?”6TheLogicofCCGaddressedthis
objection,demonstratingthat,undercertainassumptionsregardingthebehaviorofatrier
offactinresponsetoprior-awardinformation,CCGcanimproveawardsforpainand
sufferingandpunitivedamagesunderarobustrangeofconditions.
Thus,theobjectiveofthecurrentstudyistoexaminetheeffectofCCGonawardsfor
painandsufferingandpunitivedamages.Inparticular,wepresentandinterprettheresults
ofafactorialexperimentdesignedtotesttheeffectsofCCGatdifferentlevelsofbias,
variability,andformofpresentation,aswellasinteractiveeffects,onthemagnitude,spread,
4SeegenerallyTheLogicofCCG.
5Seeid.at11-21.
6Id.at5.
154
andaccuracyofawardsforpainandsufferingandpunitivedamages.Weexaminethe
behavioroftriersoffactinresponsetoCCG,andwhetherCCGimprovesaccuracy—thatis,
whetheritsbeneficialeffectonthedispersionofawardsoutweighsanyerrorresulting
fromthedistortionofthemagnitudeofawards—underarobustsetofbias,variability,and
formconditions.
Insummary,wefindstrongevidencethatprior-awardinformationimproves
accuracy,andthatitsbeneficialeffectonthedispersionofawardsgenerallydominatesany
distortionary,orbiasing,effectonawards.Furthermore,wefindstrongevidencethattriers
offactrespondtoprior-awardinformationaspredictedinTheLogicofCCG,andinline
withthe“optimal”useofsuchinformation.
Section2providesabriefoverviewoftheproblem—thevariabilityofawardsfor
painandsufferingandpunitivedamages—anddescribesanumberofmethods,andCCG
methodsinparticular,proposedtoaddressit.Section3explainsthemethodologyofthe
presentresearch,andtheexperimentinparticular.Section4reportsandinterpretsour
results.AndSection5concludes.
2. AddressingtheVariabilityofAwardsforPainandSufferingandPunitive
DamageswithComparable-CaseGuidance
2.1 CurrentMethodsandProposalsforReducingVariability
Awardsforpainandsufferingandpunitivedamagesarenotoriouslyunpredictable.7
TheSupremeCourt,lowercourts,andnumerouscommentatorshaveexpressedconcern
7SeeRandallR.Bovbjergetal.,ValuingLifeandLimbinTort:Scheduling”PainandSuffering,”83NW.U.L.REV.908,919-24(1989)(“Tortlaw’straditionalmethodsofcomputingdamagesforpersonalinjuryanddeathareunderattack—andunderstandablyso.Legalreformershavelongarguedthatpresentlaw,whencombinedwithjurydiscretion,inflatesdamageawardsandcreatesproblematicoutcomevariability.Theopen-ended
155
forthevariabilityofsuchawardsongroundsoffairness,deterrence,andtheruinous
effectsofsuchawardsonbusinessesandindustries,andonsociety’strustinthecourts.8
Courtsandcommentatorshaveproposedandimplementedvariousmethodsfor
addressingtheunpredictabilityofawardsforpainandsufferingandpunitivedamages,but
nonehasprevailedasbothadequateandappropriate.
andunpredictablenatureoftortexposurehas,inturn,threatenedtheliabilityinsurancesystemthatfundsmosttortcompensation.”);ShariSeidmanDiamondetal.,JurorJudgmentsAboutLiabilityandDamages:SourcesofVariabilityandWaystoIncreaseConsistency,48DEPAULL.REV.301,317(1998)(examiningthe“considerablevariationinbothjurorandjuryawards”);OscarG.Chase,HelpingJurorsDeterminePainandSufferingAwards,23HOFSTRAL.REV.763,768-69(1995)(citingstudies);DavidW.Leebron,FinalMoments:DamagesForPainandSufferingPriortoDeath,64N.Y.U.L.REV.256,259(1989)(“Thedata...suggestthattortawardsforeventhisrelativelysimplearea[painandsufferingpriortodeath]varysignificantlyandthatneitherthespecificfactsofthecasenordifferingtheoreticalviewsofthefunctionsoftheawardscanexplainsuchvariation”);JoniHerschandW.KipViscusi,PunitiveDamages:HowJudgesandJuriesPerform,33J.LEG.STUD.1,1-3,4-10(2004)(examiningunpredictableawardsforpunitivedamages);seealsoTheLogicofCCGat1-5(citingcasesandliterature).ButseeTheodoreEisenbergetal.,VariabilityinPunitiveDamages:EmpiricallyAssessingExxonShippingCo.v.Baker,166JOURNALOFINSTITUTIONALANDTHEORETICALECONOMICS5(findingthatthedatadoes“notsupporttheunpredictabilityconcern”);Yun-chienChangetal.,PainandSufferingDamagesinPersonalInjuryCases:AnEmpiricalStudy,UNIV.OFCHICAGOCOASE-SANDORINST.FORLAW&ECON.ResearchPaperNo.749(April12,2016),http://papers.ssrn.com/abstract=2741180(“painandsufferingdamagesinTaiwanaretoalargeextentstatisticallyandlegallypredictable”).SeegenerallyNeilVidmar&MiryaHolman,TheFrequency,Predictability,andProportionalityofJuryAwardsofPunitiveDamagesinStateCourtsin2005:ANewAudit,43SUFFOLKU.L.REV.855(2010).
8See,e.g.,ExxonShippingCo.v.Baker,554U.S.471,499(2008)(“Therealproblem,itseems,isthestarkunpredictabilityofpunitiveawards”;“[t]hus,apenaltyshouldbereasonablypredictableinitsseverity,sothatevenJusticeHolmes’s‘badman’canlookaheadwithsomeabilitytoknowwhatthestakesareinchoosingonecourseofactionoranother.Andwhenthebadman’scounterpartsturnupfromtimetotime,thepenaltyschemetheyfaceoughttothreatenthemwithafairprobabilityofsufferinginlikedegreewhentheywreaklikedamage.”(citingOliverWendellHolmes,ThePathoftheLaw,10HARV.L.REV.457,459(1897)));BMWofNorthAmerica,Inc.v.Gore,517U.S.559,574(1996)(“Elementarynotionsoffairnessenshrinedinourconstitutionaljurisprudencedictatethatapersonreceivefairnoticenotonlyoftheconductthatwillsubjecthimtopunishment,butalsooftheseverityofthepenaltythataStatemayimpose”);Paynev.Jones,711F.3d85,94(2dCir.2013)(“Apartfromimpairingthefairness,predictabilityandproportionalityofthelegalsystem,judgmentsawardingunreasonableamountsasdamagesimposeharmful,burdensomecostsonsociety”);Geressyv.DigitalEquip.Corp.,980F.Supp.640,656(E.D.N.Y.1997)(commentingonthe“virtuallyunbridleddiscretion”ofjuriesindecidingawardsforpainandsuffering);Chase,supranote7,at768-69(“Variabilityisaproblemprimarilybecauseitunderminesthelegalsystem’sclaimthatlikecaseswillbetreatedalike;thepromiseofequaljusticeunderlawisanimportantjustificationforourlegalsystem.Variabilityisalsoclaimedtocreateinstrumentaldefects....”);Bovbjergetal.,supranote7,at908(“Determinationofawardsonanadhocandunpredictablebasis,especiallyfor‘non-economic’losses...tendstosubvertthecredibilityofawardsandhindertheefficientoperationofthetortlaw’sdeterrencefunction”);seealsoTheLogicofCCGat5-8(citingrelevantcasesandliterature).
156
First,courtscurrentlyusetheproceduresofadditurandremittitur—wherebya
courtthatfindsanawardtobeinadequateorexcessivemayorderanewtrialifthelitigant
harmedbytheproceduredoesnotagreetoanincrease(additur)orareduction
(remittitur)oftheaward.9Butthesedevicesaregenerallyinadequateastoolsfor
addressingvariability.Theyareappliedinconsistentlyandwithminimalstandards10;they
areusedtoaddressonlythemostextremeawardsratherthanvariabilitygenerally;and
regularuseofsuchmethods,andreplacementofjurydeterminationswiththoseofthe
court,wouldarguablyraisesignificantconstitutionalproblemsandbeinconsistentwith
fundamentalprinciplesoftortlaw.11Additionally,thesemethodsserveasa“band-aid”
ratherthanaddressingtheunderlyingproblem—thatjuriesreceiveinsufficientguidancein
assessingawardsforpainandsufferingandpunitivedamages.12
Second,numerousjurisdictionshaveimposeddamagecapstoaddressextreme
awards.Legislatureshaveenacteddamagecapsforcertaintypesofawards,suchas
9SeeDavidBaldusetal.,ImprovingJudicialOversightofJuryDamagesAssessments:AProposalfortheComparativeAdditur/RemittiturReviewofAwardsforNonpecuniaryHarmsandPunitiveDamages,80IOWAL.REV.1109,1118-20(1995).
10Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001)(“[Mostcourts]treatthedeterminationofhowmuchdamagesforpainandsufferingtoawardasastandardless,unguidedexerciseofdiscretionbythetrieroffact,reviewableforabuseofdiscretionpursuanttonostandardtoguidethereviewingcourteither.”).
11SeeBaldus,supranote9;TheLogicofCCGat8-9.ButseeCassSunsteinetal.,PunitiveDamages:HowJuriesDecide248-52(2002)(arguingforalargerjudicialroleindeterminingpunitivedamages).Notethat,althoughourfocusisonmethodsthatmaintainthediscretionofthejury,asinTheLogicofCCG,ouranalysisregardingCCGmethodscaneasilybeextendedtoproceduresinwhichthecourthasamoresubstantialrole(onreview,orinthefirstinstance)indecidingawardsforpainandsufferingandpunitivedamages.
12Note,TheLogicofCCGproposestheuseofCCGinadditiontotheproceduresofadditurandremittitur,andnotinplaceofthem.
157
punitivedamages,ordamageawardsgenerally.13However,damagecapsaddressonly
extremecases,andonlyexcessiveawards.14Moreover,cappingawardsgenerallywithout
regardfortheindividualcircumstancesofacasegivesrisetofairnessandproportionality
concerns,andcanharmthedeterrenceobjectivesoftortlawanddisincentivizebeneficial
lawsuits.15Theymayraiseconstitutionalconcernsaswell.16
Third,anumberofcommentatorshaveproposedusingawardsincomparablecases
asguidanceforawarddeterminations.Thesemethodshavebeenproposedinvarious
forms.Somehavefocusedontheuseofcomparablecasesonreview,andtheimportanceof
creatingamoreprincipledapproachtoatrialcourt’sreviewofawardsforexcessiveness.17
However,althoughsuchmethodsimprovethestandardsunderlyingacourt’sreview,they
sufferfrommanyofthesameproblemsthatapplytotheproceduresofadditurand
remittiturgenerally.Forexample,theyaddressonlyextremeawards,andregular
replacementofthejury’sdiscretionwiththatofthecourtarguablygivesrisetoarangeof
constitutionalandsubstantivetortproblems.
Similarissuesarisefrommethodsthatinvolvebindingthetrieroffacttoa
particularawardorrangeofawards,orthatpredetermineascheduleofawardsinadvance
13SeeJosephSanders,WhyDoProposalsDesignedtoControlVariabilityinGeneralDamages(Generally)FallonDeafEars?(andWhyThisIsTooBad),55DEPAULL.REV.489,510(2006).
14TheLogicofCCGat9.
15SeeSanders,supranote13,at509-11;TheLogicofCCGat9.
16KathrynZeiler,TurningfromDamageCapstoInformationDisclosure:AnAlternativetoTortReform,5YALEJ.HEALTHPOL’Y,L.ÐICS385,387(2005).
17See,e.g.,Baldus,supranote9.
158
ofacase.Thesemethodshavesimilarlybeencriticizedasreplacingthejury’sdiscretion
withthatofthecourtoralegislativebodyaltogetherremovedfromthecase.18
Somerecommendations,however,haveinvolved“comparabilityanalysis,”whereby
acourtidentifiescomparablecases,providesthetrieroffactwithinformationregarding
theawardsinthesecases,andinstructsthetrieroffacttoarriveatadamagesawardbased
ontheevidence,andusingthecomparable-caseinformationasguidance.19These
recommendationsarebasedonstudiesdemonstratingthattheyareeffectiveincontrolling
outlyingawardsandvariabilitygenerally(evenwhensuchinformationisprovidedasnon-
bindingguidance).20
2.2 Comparable-CaseGuidance
TheLogicofCCGexaminesaspecifictypeofcomparabilityanalysis.Itdefinesthe
termcomparable-caseguidance(CCG)as:
schedulingorcomparability-analysismethods that fulfill three fundamentalrequirements: 1) informationusedasguidancemustbederivedfromprior“comparable” cases (as opposed to, e.g., damage schedules predeterminedarbitrarily by a legislative body); 2) comparable-case informationmust beconsidered by the fact-finder in particular (as opposed to, e.g., a reviewingcourt);and3)comparable-caseinformationmustbeusedasguidanceonly(as
18TheLogicofCCGat10;seeDavidA.Logan,Juries,Judges,andthePoliticsofTortReform,83U.CIN.L.REV.903,942-43(2015)(“Suchanapproachwouldstreamlinelitigationandgreatlylimit,ifnoteliminate,theconcernswithvariabilityandfairnessthatthecurrentpracticerisksbytreatinglikecasesdifferently.However,thisapproachisfatallyflawedbecauseitevisceratesthevariouscontributionsthatjuriesmaketotheciviljusticesystem.Moreover,thisapproachisfundamentallyinconsistentwiththebasictortprinciplethateachvictimisentitledtoanawardtailoredtohisorhercircumstances,setbyalayjury.”(citingtheRestatement(Second)ofTorts§901cmt.a(1979))).
19TheLogicofCCGat3.
20SeeMichaelJ.Saksetal.,ReducingVariabilityinCivilJuryAwards,21LAWANDHUMANBEHAVIOR243,249-55(1997).
159
opposed to, e.g., imposing a range or amount that is binding on the fact-finder).21
Numerouscourtsandcommentatorshavecalledforsuchmethods.Consider,for
examplethecaseJutzi-Johnsonv.UnitedStates,whichinvolvedanappealfromanawardfor
painandsufferingresultingfromabenchtrial.22Inthatcase,JudgeRichardPosner
commentedonthe“acute”problemof“figuringouthowtovaluepainandsuffering.”23
AccordingtoJudgePosner,notwithstanding“varioussolutions,nonewhollysatisfactory,
[that]havebeensuggested,”“[m]ostcourtsdonotfollowanyoftheseapproaches.Instead
theytreatthedeterminationofhowmuchdamagesforpainandsufferingtoawardasa
standardless,unguidedexerciseofdiscretionbythetrieroffact,reviewableforabuseof
discretionpursuanttonostandardtoguidethereviewingcourteither.”24Heconcluded
that“[t]ominimizethearbitraryvarianceinawardsboundtoresultfromsuchathrow-up-
the-handsapproach,thetrieroffactshould,asisdoneroutinelyinEngland...beinformed
oftheamountsofpainandsufferingdamagesawardedinsimilarcases.”25Hecontinued:
“Andwhenthetrieroffactisajudge,heshouldberequiredaspartofhisRule52(a)
obligationtosetforthinhisopinionthedamagesawardsthatheconsideredcomparable,”
notingthatcourts“makesuchcomparisonsroutinelyinreviewingpainandsuffering
21TheLogicofCCGat4.
22263F.3d753(7thCir.2001)
23Id.at758.
24Id.at758-59.
25Id.(internalcitationsomitted).
160
awards,”andremarkingthat“[i]twouldbeawisepracticetofollowatthetriallevelas
well.”26
However,callsforsuchmethodshavegenerallyfailed.Indeed,therehavebeen
substantialobjectionstothesemethodsongroundsthattheirvalidityreliesontheability
ofacourttoreliablyidentifyanappropriatesetof“comparable”casesforguidancethat
wouldimprovetheawardathand.27ThefundamentalissueisnotwhetherCCGreduces
variability—itiswhetherCCGimprovesawards.
TheLogicofCCGthusaddressesafundamentalobjection:“howisitbeneficialto
provideafact-finderwithinformationregardingdamagesawardedinpriorcasesthatare
separateanddistinctfromthepresentcaseandthatpresumablysufferfromthesame
arbitrarinessthatwewishtoaddressinthepresentcase?”28Inessence,thepaperexplains
how“CCGmethodsreduceunpredictabilityandimproveawardsforpainandsufferingand
punitivedamagesbyallowingforthesharingofrelevantinformationacrosscases”;and
26Id.(internalcitationsomitted).SeealsoRoselleWissleretal,DecisionmakingAboutGeneralDamages:AComparisonofJurors,Judges,andLawyers,98MICH.L.REV.751(1999)(discussing“reformsconsistentwiththeavailabledata,”suggesting,“[a]notherpowerfulyetmodestreformwouldbetopooljuryawardsmadeforsimilarinjuries,andtopresentthesecasesandtheirawarddistributionstojuriesforguidanceinreachingtheirgeneraldamagesawardsandtojudgesforconductingtheiraddituir/remittiturreviews”);Chase,supranote7,at775,777-90(discussingrecommendationbytheABAActionCommissiontoImprovetheTortLiabilitySystemtoestablish“’tortawardcommissions’establishedtogatherandreportinformationthatwouldbeusefulin‘theframingofjuryinstructions,theexerciseofthepowerofadditurandremittitur,andtheprocessofsettlingcases,’”id.at775(quotingAmericanBarAssoc.,ReportoftheActionCommissiontoImprovetheTortLiabilitySystem10-15(1987)),andproposingmethodinvolvingchartsprovidingnonbindingguidance“toallowcomparisonwithroughlysimilarcasesinwhichplaintiffs’verdictswererecovered.”Id.at777-90);Sanders,supranote13,at496-507(describingproposalsandstudies);Logan,supranote18,at939-44(discussingproposals).
27SeeTheLogicofCCGat4-5.
28Id.at5.
161
howitdoessowithsuchconsistencythat(extraordinarycircumstancesaside)acourtneed
notbeconcernedwithwhetherCCGwillimproveaccuracyinaparticularcase.29
TheconclusionsinTheLogicofCCGarepremisedonthenotionthatfundamental
toagoodmethodofaddressingawardvariabilityistheabilityofthemethodtoreduce,
notonlyvariability,buterror:“reducingvariabilitydoesnotnecessarilymeanimproving
theaward.Forexample,itislikelyunwisetoencouragejurorstoanchortoanarbitrary
value,notwithstandingassociatedvariabilitybenefits.Infact,variabilitycouldbezeroif
thecourtweretodictateanawardwithoutregardtotheparticularsofthecase.”30Thus,
although“[c]ourtsandscholarsarecorrecttobeconcernedaboutthehighvariability
associatedwithawardsforpainandsufferingandpunitivedamages,”“goodpolicy
requiresstepstowardreducingsuchvariabilityonlyinsofarastheyimproveawards
generally.”31
TheLogicofCCG,therefore,buildsuponaframeworkforanalyzingthe“accuracy”
ofdamageawards.ItconcludesthatCCGcanimproveawardsforpainandsufferingand
punitivedamagesunderarobustsetofconditions—andspecifically,conditionsregarding
the“appropriateness”ofthepriorawardsidentified.Inotherwords,itconcludesthatthe
validityofCCGisnotverysensitiveto,andthereforedoesnotdependheavilyon,the
abilityofacourttoidentifyan“appropriate”setof“comparable”cases.
29Id.
30Id.
31Id.at11-12.
162
Butitsconclusionsregardingtherobustnessofsuchmethodsrelyoncertain
untestedbehavioralassumptions.Thecurrentpaper,therefore,aimstotestthe
propositionthatCCGnotonlyreducesthevariabilityofawards,butimprovesawards
underarobustsetofconditions.Ifsuchclaimsaresupportedbythedata,theymaydefuse
themajorobjectionstoCCGmethods,andmayweighheavilyinfavoroftheuseofthese
methodsinthecourtroom.
Inthefollowingsubsection,wedescribetheframeworkestablishedinTheLogicof
CCGforanalyzingtheaccuracybenefitsofCCG.
2.3 ReducingVariabilityandErrorwithCCG
TheLogicofCCGdefinesthe“correct”awardinacaseastheawardthatwouldresult
ifthecourthadperfectinformationregardingboththelawandthefactsofthecase.32It
explains,however,that“weneitherhaveperfectinformationnorknowthecorrectaward.
Instead,thecourtasksajurytoarriveatanaward,whichwillserveasanestimateofthe
correctoutcome.”33Itfurthercharacterizesthe“correct”awardas“themeanofthe
populationofpossibleawardsthatwouldemergefromadjudicatingthecaserepeatedly
undervariousconditions(e.g.,beforedifferentjudgesandjuries,bydifferentattorneys,
withdifferentpermutationsoffacts,etc.).”34Thus,“[a]singletrial…generatesasample
32Seeid.at12(citingHillelJ.Bavli,AggregatingforAccuracy:ACloserLookatSamplingandAccuracyinClassActionLitigation,14LAW,PROBABILITY&RISK67,74-78(2015)[hereinafterAggregatingforAccuracy]).Note,wecansimilarlydefineadistributionof“correct”awardsreflecting,e.g.,uncertaintyregardingthelaw.SeeHillelJ.Bavli,SamplingandReliabilityinClassActionLitigation,2016CARD.L.REV.DENOVO207,209n.16(2016).
33TheLogicofCCGat12.
34 Id. (citingAggregating forAccuracy at74-78(citingMichael J. Saks&PeterDavidBlanck, JusticeImproved:TheUnrecognizedBenefitsofAggregationandSamplingintheTrialofMassTorts,44STAN.L.REV.815,833-34(1992))).Thischaracterizationisintendedtocapturevariousinterpretationsofthe
163
fromthepopulationandanestimateofthecorrectaward.Calltheactualawardan
‘estimate,’andtheprocedurethatgeneratestheestimatean‘estimator.’Wecanthendefine
‘error’intermsofdistance,and(equivalently)‘accuracy’intermsofproximity,between
theestimateandthecorrectaward.”35The“reliability”ofalegalprocedureisthendefined
astheaccuracyoftheawardthatcanbeexpectedbyfollowingtheprocedure.36
Morespecifically,errorisdefinedbymeansquarederror(MSE),whichcanbe
separatedinto“bias”and“variance.”Biasrepresentssystematicerror,orthedifference
betweentheexpected,oraverage,awardandthe“correct”award.37Variance,ontheother
hand,isameasureofdispersion—thevariabilityoftheawardarounditsmean.Thus,
If theestimatorentailsahigh levelofvariance,but isunbiased, then itwillgenerateestimates[i.e.,awards]thatarehighlydispersedaroundthecorrectvalue. Inthiscase,wesaythattheestimatoris“unbiased,”butthatit lacks“precision.”Iftheestimatoris“precise”but“biased,”thenitgeneratesvaluesthat are tightly centered around the wrong value—an undesirablecircumstance.Ifanestimatoris“precise”and“unbiased,”thenitwillgenerateestimatesthatarecloseinproximitytothecorrectvalue,andwesaythatitis“accurate.”38
law,thefactsofthecase,norms,etc.Id.at12n.51.Thereareinfactmanyreasonabledefinitionsforthe “correct” award in a case. Even using the conceptualization above, other measures of centraltendency—suchas themedian—maybeused, dependingonourbeliefs regarding thebestway tocharacterize the “correct” award (e.g.,whetherwewant to capture information regardingextremevalues,etc.).Additionally,asdiscussedinfra§3,forpurposesofthecurrentstudy,itisnotnecessaryto define a “correct” award. We do so for purposes of clarity, and for consistency with previousliterature.
35Id.(citingAggregatingforAccuracyat74-78).
36Id.
37Id.at13.
38Id.
164
Therefore,error(andthusaccuracy)ismeasuredintermsofbiasandvariance.The
LogicofCCGmodelsawardsforpainandsufferingandpunitivedamagesformally,
examiningtwoformsofvariability—claimvariability,reflectingsubstantive(factual)
differencesfromclaimtoclaim,andjudgmentvariability,reflectingrandomvariation
associatedwiththeawardofagivenclaim.39Itexplainsthat“wewanttheestimateto
reflectthefirstformofvariability—thatmeaningfulfactualdifferences(e.g.,betweenthe
presentcaseandpriorcases)shouldresultindifferentawards.Ontheotherhand,wewant
tominimizethesecondformofvariability—therandomnessassociatedwiththe
determinationofdamagesinagivencase.”40ItdescribesthebenefitofCCGasfollows:
Unfortunately,sincewegenerallydonotknowthecorrectdamagesaward,itisimpossibletodistinguishtheformerformofvariabilityfromthelatter.Inotherwords,atradeoffarisesbetweenminimizingbias—thatourestimateddamagesawardshould,onaverage,beasclosetothecorrectdamagesawardas possible, reflecting the former form of variability—and minimizingvariance, the degree of randomness associated with the estimated award.Thus, in a sense, incorporating prior-award information as guidance indeterminingadamages awardallows the fact-finder (implicitly) to strike abalancebetweenbiasandvariancesoastominimizeerror.Byacceptingthepossibilityofintroducingsomebiasduetomaterialdifferencesbetweenthepresent case and prior cases, it is possible to gain far more, in terms ofreliability, due to the reduction in awardvariability that follows fromsuchguidance.41Butwhatbalanceshouldthetrieroffactstrikebetweenprior-awardinformation
andthefactsofthecaseathand?ConsidertwoextremescenariosdescribedinTheLogicof
CCG.First,assumethatthetrieroffactbasesitsawardentirelyonthepriorawards
39Id.at16(citingAggregatingforAccuracyat74-78).
40Id.at16-17.
41Id.at17.
165
providedtoit—say,forexample,thatitsimplyappliestheaverageofthepriorawardsas
itsawarddetermination.Inthiscase,therewouldbenoerrorcausedbyrandomvariation,
sincetheaverageofthepriorawardsisconstant,“buttotheextentthattheaverageofthe
priorawardsisdifferentfromthecorrectcurrentaward…therewillbesubstantialerror
frombias.”42Assume,ontheotherhand,thatthetrieroffactdecidesthatitwillnoteven
considertheprior-awardinformationaspartofitsawarddetermination—thatitwill
determineanawardbasedsolelyontheevidence.Inthiscase,assumingtheawardis
unbiasedinthefirstinstance,“therewillbenoerrorfrombiasbutsubstantialerrorfrom
variability.”43
Thus,“CCGimprovesthereliabilityofawardsforpainandsufferingandpunitive
damages—awardtypesthatsufferfromparticularlyhighdegreesofvariability—by
facilitatingabalancebetweenminimizingvariabilityandintroducingthepossibilityof
bias.”44
Mathematically,itispossibletoderivetheoptimallevelofinfluenceoftheprior-
awardinformation.Theidealinfluenceisbasedontherandomvariationoftheaward
determination(i.e.,judgmentvariability)andthevariabilityofthepriorawards(i.e.,
claimvariability).45“Higherjudgmentvariabilitysuggestsweakerinformationobtained
fromthepresentcaseandgreaterinfluenceofthepriorawards;higherclaimvariability
42Id.
43Id.
44Id.at18.
45Id.
166
suggestsweakerinformationobtainedfromthepriorcases(and,similarly,higher
potentialforbias)andgreaterinfluenceofthepresentcase.”46
Forexample,wherejudgmentvariabilityisextremelylow,andmultiple
adjudicationsyieldidenticaloutcomes,“thereislittletobegainedfromintroducing
prior-awardinformationandthepossibilityofbias.”47Wherejudgmentvariabilityis
high,however(asisoftenthecasewithawardsforpainandsufferingandpunitive
damages),thereismuchtobegainedfromprior-awardinformation.48Similarly,highly
variablepriorawardssuggest,e.g.,thepossibilityofsignificantdifferencesamongtheset
ofcases—relativetoeachotherandrelativetothesubjectcase—andlessguidancefor
theawarddetermination;whereaspriorawardswithlowvariabilityprovideclearer
information,and,inasense,strongerguidance.49
Thus,itistheoreticallypossibleto1)estimateclaimvariability,e.g.,bycomputing
thevarianceofthepriorawards,2)estimatejudgmentvariability,e.g.,bycomputingthe
varianceofawardsresultingfromrepeatedadjudications,and3)arriveatanaward(an
estimateofthe“correct”award)formulaicallyby,e.g.,computingaweightedaverageofthe
meanofthepriorawardsandthemeanoftherepeatedadjudications,weightedbythe
46Id.
47Id.
48Id.
49Id.
167
inverseofthevarianceofeach,respectively.50Statisticiansrefertothistypeofestimatoras
a“shrinkage”estimator.51
Buttwoproblemsarise.First,itisdifficultandcostlytocomputejudgment
variabilityandgenerallyimpossibletoknowwhetherasetofpriorawardsis“aligned”
with—orhasthesamecenteras—the“correct”awardinthesubjectcase.Therefore,a
courtwouldbeunabletodeterminetheappropriateinfluenceofthepriorawardsor
whetherCCGwouldbebeneficialornot(orevenharmful)fortheawardathandinthefirst
instance.Second,thebenefitsofCCGaregroundedinassumptionsthatatrieroffactwould
actaspredicted,andthatdoingsowouldindeedimproveaccuracy.Buthowdoweknow
thatsuchassumptionsarejustified?
TheLogicofCCGaddressesthefirstproblembyexplainingthatitisunnecessary
tocomputejudgmentvariabilityorwhetherCCGisbeneficialinaparticularcase.That
paperarguesthat,inlightofthevariabilityofawardsforpainandsufferingandpunitive
damages,andtherobustnessoftheaccuracybenefitsofCCGunderawiderangeof
conditions,includingthoseinvolvingpriorawardsthatarenot“aligned”withthe
“correct”award,courtsshouldtrustthat,absentextraordinarycircumstances,a
reasonableprocedureforidentifyingpriorawardswillresultinCCGhighlylikelyto
improveaccuracy.“Statistically(usingfundamentalsof‘shrinkageestimation’),
50SeeHillelJ.Bavli&YangChen,ShrinkageEstimationintheAdjudicationofCivilDamageClaims,REV.OFL.&ECON.(forthcoming,2017),foranexaminationofaformulaicapplicationofthisapproach.
51SeeTheLogicofCCGat15-16,18-19n.65.SeealsoBradleyEfron&CarlMorris,DataAnalysisUsingStein’sEstimatorandItsGeneralizations,70J.OFTHEAM.STATISTICALASS’N311,312-14(1975);BradleyEfron&CarlMorris,Stein’sParadoxinStatistics,236SCIENTIFICAMERICAN119(1977).
168
incorporatingprior-awardinformationwillgenerallyimprovereliability,aslongasthe
priorawardsarenottightlybound(i.e.,withlowvariability)aroundameanthatisfar
fromthecorrectawardinthepresentcase—inpractice,aslongasthepriorawardsare
nottightlyclusteredaroundanawardthatreflectsfactsmateriallydissimilartothe
presentcase.”52Thepaperconcludesthat“[i]nshort,wecanexpectthatareasonable
methodforidentifyingprior‘comparable’caseswillresultinprior-awardinformation
thatislikelytoimprovereliability.”53
Thesecondproblem,regardingwhetheratrieroffactwouldactaspredicted
inresponsetoCCG,andwhetherdoingsowouldinfactimproveaccuracyina
robustrangeofcircumstances—notwithstandingtheconcernsexpressedabove—is
thesubjectofourexaminationinthecurrentstudy.
Specifically,ourprimaryobjectivesaretoexamine1)whetherprior-award
informationimprovesaccuracyunderarobustsetofconditionsrelatedtothebias,
variability,andformofpriorawards,and2)whethertriersoffactrespondtoprior-
awardinformationaspredicted,astojustifytheassumptionsandconclusionsinThe
LogicofCCG.
Therehavebeenanumberofstudiesexaminingtheunpredictabilityof
awarddeterminationsandmethodsofaddressingit.54Thesurveyexperimentby
52TheLogicofCCGat20-21(internalcitationsomitted).
53Id.at21.
54See,e.g.,Saksetal.,supranote20;Diamondetal.,supranote8;Bovbjergetal,supranote7;Baldusetal.,supranote9;CatherineM.Sharkey,UnintendedConsequencesofMedicalMalpracticeDamagesCaps,80N.Y.U.L.REV.391(2005);Leebron,supranote7.SeealsoSanders,supranote13,at496-507(summarizingproposalsandstudies);Chase,supranote7.
169
ProfessorSaksetal.ismostcloselyrelatedtothecurrentstudy.55Thatstudy
investigatedtheeffectsofprior-awardinformation,invariousforms,ontheamount
awardedforpainandsufferinginpersonalinjurycases—andspecifically,with
respecttoawardvariabilityand“distortions”intheamountsawarded.56Prior-
awardformstestedintheirstudyincludean“interval,”an“average,”an“average-
plus-interval,”“examples,”anda“cap”condition.Thestudyinvolvedthreedifferent
“severity”levels,whichdeterminedtheseverityoftheinjuryatissueinafact-
patternprovidedtoparticipants.Each“guidancecondition”waspredetermined
basedontheresultsofapilotstudy.Forexample,theauthorsusedthemedianof
thepilotstudytodefinethe“average”condition,the10thand90thpercentilesto
definethe“interval”condition,the10th,50th,and90thpercentilestodefinethe
“average-plus-intervals”condition,andthe10th,35th,65th,and90thpercentilesto
definethe“examples”condition.57
Insummary,theauthorsfoundthatthe“interval,”“average-plus-interval,”
and“examples”conditionscausedareductioninvariability,whiledistortingaward
amountsminimallyornotatall.58Theyalsofoundthatthe“cap”condition
performedpoorlyandsometimesincreasedthevariabilityandsizeofawards.59
55SeeSaksetal.,supranote20,at246.
56Seeid.at246-47.
57Seeid.at248.
58Seeid.at246.
59Seeid.at253.
170
AlthoughthesubjectofthestudybySaksetal.,anditsuseofpilotdatatoestablish
guidanceconditions,aresimilartothoseofthepresentstudy,thedetailsofthedesignand
analysisofthepresentstudydiffersubstantiallyfromthoseofthestudybySaksetal.and
otherstudies.Mostfundamentally,ourresearchdiffersfromallpreviousstudiesinits
focusonaccuracy,aswellasspreadandmagnitude,underarobustsetofbias,variability,
andformconditions.Thepresentstudyisalsouniqueinitsfocusonthebehavioralaspects
ofthemodelpresentedinTheLogicofCCG,including,forexample,testingtheeffectof
prior-awardvariabilityonamountsawarded.
3. Methodology
Ourobjectiveistotesttheeffectsofprior-awardinformationatdifferentlevelsof
bias,variability,andform,andtheirinteractions,onthemagnitude,spread,and,accuracyof
awardsforpainandsufferingandpunitivedamages.Wetesttheseeffectsexperimentally
(i.e.,byimposinganintervention)usingafactorialdesignandthepotentialoutcomes
framework.60Thismeansthateachoftheparticipantsisexposedtoa“treatment
combination”(or“treatmentcondition”)—intheformofasurvey—arisingfromasetof
“factors,”eachofwhichcanbesettoacertainvalue,or“level,”61andthatwemakecausal
conclusionsbasedoninferencesaboutwhatanoutcomewouldbeunderexposureto
60SeeTirthankarDasgupta,NateshS.Pillai,&DonaldB.Rubin,CausalInferencefrom2KFactorialDesignsbyUsingPotentialOutcomes,77(4)J.OFTHEROYALSTAT.SOC.SERIESB(STAT.METHODOLOGY)727,727(2015)[hereinafter2KFactorialDesigns];DonaldB.Rubin,EstimatingCausalEffectsofTreatmentsinRandomizedandNonrandomizedStudies,66(5)J.OFED.PSYCH.688(1974).Weusethenotationandgeneralframeworkestablishedin2KFactorialDesignsbutextendthenotationtoaccommodatetheadditionallevelspresentinthisexperiment.
61Seegenerally2KFactorialDesigns.
171
alternativetreatmentcombinations.62Inthecurrentsection,wedescribeourmethodology,
includingthedetailsofourexperimentaldesign(“theDesign”)andouranalysis.
3.1 SurveyAdministration
WeusedAmazon’sMechanicalTurktorecruitandadministersurveysto5500
participantssimilartoindividualsfoundonU.S.juries(U.S.citizenswhoare18orolder
andEnglishspeaking).63Participantsenrolledintheexperimentsequentiallyandwere
randomlyassignedtoreceiveoneof22surveys,eachreflectingaspecifictreatment
combination,whichdeterminedwhatprior-awardinformation,ifany,theparticipant
receivedasguidanceinrespondingtothesurvey.64Ineachsurvey,participantswere
presentedwithafactpattern,instructions,andcertainguidancefordeterminingadamages
award,basedontheassignedtreatmentcombination.Theywerethenaskedtodeterminea
62SeegenerallyRubin,supranote60,at689-90;C.F.JeffWu&MichaelS.Hamada,Experiments:Planning,Analysis,andOptimization(2ded.2009).
63MechanicalTurkrequiresthatallparticipantsbe18orolderandEnglishspeaking.TheU.S.citizenshiprequirementwasdifficulttoenforce;butweattemptedtoenforceditbyrequiringthatallparticipantshaveanIPaddresslocatedwithintheU.S.Additionally,weprovidedinformationregardingeligibilityrequirementstoallpotentialparticipantsandaskedthattheyparticipateinthesurveyonlyiftheymetthestatedrequirements.Notethatweignoredsomequalificationsforjuryservice,suchastherequirementthattheparticipantnotbeaconvictedfelon.
64Toensureroughlyequalsamplesizesacrosstreatmentgroups,a“dynamicrandomizationscheme”wasused.Thisschemepreventsanysingletreatmentconditionfromhavingmorethantwomoreparticipantsthananyotherconditionatanystageoftherandomization.Forexample,ifthefirsttwoparticipantstoenrollinthestudywererandomlyassignedtocondition1,thenextparticipantwhoenrolledinthestudywouldberandomlyassignedtooneoftheremainingtwenty-oneconditions.Thisschemecanbeviewedasaformof“blockrandomization,”whichmaintainsthepropertiesofclassicalrandomization,assumingtheparticipantsenrollrandomly(inthesensethatoneindividual’senrollmentdoesnotaffectanother’ssubsequentenrollmentotherthanthroughtherestrictiononthenumberofunitsineachtreatmentcondition).
172
damagesaward,provideanoptionalexplanation,andprovidecertaindemographic
information.65Theprimaryoutcomeinthisstudyistheawardamount.66
3.2 TreatmentCombinations
ForpurposesoftheDesign,theexperimentcanbeunderstoodastwoseparate
studies:acontrolstudywherenopriorawardinformationisavailableandatreatment
studywherepriorawardinformationisprovided.67Thecontrolstudyhasone
experimentalfactor:scenario(2levels).Thetreatmentstudyhasfourexperimental
factors:scenario(2levels),form(3levels),bias(2levels),andvariability(2levels).
Scenariocanbesettooneoftwolevels:painandsufferingorpunitivedamages.
Formcanbesettooneofthreelevels:average,list,orrange.Biascanbesettooneoftwo
levels:unbiasedorbiased.AndVariabilitycanbesettooneoftwolevels:lowvariabilityor
highvariability.
Thus,eachtreatmentcombinationischaracterizedbytheleveltowhicheachfactor
isset;andthetreatmentcombinationtowhichaparticipantwasrandomizeddetermined
theparticularsurveyheorshereceived.Forexample,aparticipantrandomizedtothe
treatmentcombinationthatinvolves[scenario=painandsuffering,form=list,bias=
unbiased,andvariability=highvariability]receivedasurveythataskedtheparticipantto
65Participantsreceived$.20fortheirparticipationinthesurvey.
66Theoptionalexplanationfortheawardamountchosenwillbeanalyzedseparatelyinasecondstudy.Thisoutcomeisthereforenotaddressedinthisstudy,excepttoconfirmourexpectationthatsurveyparticipantsprovidedthoughtfulresponses,ratherthansimplyfillinginaresponsewithoutanythought.
67Thiscategorizationisconvenientforpurposesofconsideringtheexperimentalfactors.Ontheotherhand,asdiscussedfurtherbelow,ourresultsareanalyzed,andmostconvenientlyunderstood,withineachlevelofscenario.
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determineanawardforpainandsuffering,andprovidedunbiased,highvariabilityprior-
awardinformationintheformofalist.
Bydesign,certainlevelsofcertainfactorsareincompatiblewithcertainlevelsof
otherfactors.Inparticular,inthetreatmentstudythevariabilityfactorisnotapplicable
whenprior-awardinformationispresentedintheaverageform.Also,aspreviouslystated,
inthecontrolstudyonlythescenariofactorisapplicable.
Thus,thefactorsdefinetwotreatmentconditionsinthecontrolstudyand2x3x2x
2=24treatmentconditionsinthetreatmentstudy,minusfourinapplicableconditionsthat
arisefrom“crossing”thevariabilityfactorwiththeaverageleveloftheformfactor,fora
totalofJ=2+24–4=22treatmentconditions.Hereafter,werefertotheconditionswithin
thecontrolstudyasthe“controlconditions”andtheconditionswithinthetreatmentstudy
asthe“activetreatmentconditions.”Allconditionsareexplainedinmoredetailbelow.
3.3 TheSurveys
Eachsurveyforthecontrolconditionscontainsathree-paragraphstem.Thefirst
paragraphcontainsgeneralinstructions:
Thefollowingsurveyshouldtake5-10minutes.Pleasereviewtheinformationbelow, and provide your response and the demographic informationrequested.Pleasedonotconsultanyoutsidesources.Thedatawecollectwillbeusedforresearchpurposes.Wewillnotattempttoidentifyyouorconnectyourresponsestoyouridentity.Ifyouridentitybecomesknowntous,itwillremainprivate.”
Thesecondparagraphcontainsashortfactpatternthatbrieflydescribesatortcommitted
byacorporationandtheconsequencesofthetortforitsvictim.Thethirdparagraph
containsthejudge’sinstructionsforarrivingatanaward.
Asdiscussedabove,thecontrolstudyinvolvesonlyasinglefactor,scenario,which
174
hastwolevels,punitivedamagesandpainandsuffering.Thelevelofscenariodetermines
thefactpatternandthejudge’sinstructionsinthesecondandthirdparagraphsofthestem.
Inparticular,thesecondandthirdparagraphsofthepunitivedamagesscenariostate:
Youareajurorinatrialinwhichacarmanufacturerconcealeditsknowledgeofadefectinitscar’sairbagsystem.Asaresultofthedefect,theairbagswouldfail to deploy in a small proportion of frontal collisions. The lawsuit wasbroughtbyadriver,Andrew,whosufferedseverebraininjuryfromafrontalcollision caused by ice on the road. He now liveswith headaches, blurredvision,speechimpairment,andmemoryloss.Attrial,itwasestablishedthat,asaresultofthedefect,theairbagsfailedtodeploy.Itwasalsoestablishedthat,hadtheairbagsdeployedproperly,Andrew’sinjurieswouldhavebeenavoided.Thejudgehasaskedyoutodeterminea“punitivedamages”award.Heinformsyou that, through a separate proceeding, Andrew has already beencompensatedforhisinjuries,includinghismedicalexpensesandhispainandsuffering. The judge instructs you that your role now is to determine a“punitivedamages”award.Heexplainsthat“punitivedamagesaredamagesawarded not to compensate the plaintiff for any injury but to punish thedefendantforoutrageousconductandtodeterthedefendantandothersfromsimilarconductinthefuture.Youarenotrequiredtoawardpunitivedamages,andyoumayawardsuchdamagesonlyifyoufindthatthedefendant’sconductwasinfactoutrageous.”Thejudgeemphasizesthat“thereisnoexactstandardfordeterminingpunitivedamages.Youshoulddecideonanamountthatyoufind necessary for achieving the objectives described above. You shouldconsiderthedegreeofreprehensibilityofthedefendant’smisconductandtheactualorpotentialharmsufferedbytheplaintiff.”
Thesecondandthirdparagraphsofthepainandsufferingscenariostate:
You are a juror in a trial inwhich a company intentionally disposed of itsindustrialwastebyregularlydumpingitintoalocalriverratherthanhavingtheexpenseofdisposing itproperly. The lawsuitwasbroughtbyEmma,a29-year-old woman whose drinking water was affected by the improperdisposalandwhodevelopedararecancerasaresult.Threeyearsbeforeherdiagnosis,Emmamarriedhercollegeboyfriend. Sheandherhusbandnowhaveatwo-year-olddaughter.Emmahasundergonemultiplesurgeriesandmonths of chemotherapy and radiation therapy, but doctors have recentlyinformedher that thecancerhasspreadand thather likelihoodofsurvivalbeyond sixmonths is very low. Since her diagnosis one year ago, she hassufferedfromregularpain,nausea,fatigue,anddisfigurement,andherorgans
175
haverecentlybeguntofail.ThejudgehasaskedyoutodetermineasuitabledamagesawardforEmma’spainandsuffering(pastandfuture)andherlossofcapacityforenjoymentoflife.Heinformsyouthat,throughaseparateproceeding,Emmahasalreadybeencompensated forhermonetarycosts, suchaspastand futuremedicalexpenses.ThejudgeinstructsyouthatyourrolenowistodetermineanawardforEmma’sphysicalandmentalpainandsuffering(pastandfuture)andherlossofcapacityforenjoymentoflife.Thejudgeemphasizesthat“noevidenceofthevalueofintangiblethings,suchasmentalorphysicalpainandsuffering,hasbeenorneedbeintroduced.Youarenottryingtodeterminevalue,butanamount that will fairly compensate the plaintiff for the damages she hassuffered.Thereisnoexactstandardforfixingthecompensationtobeawardedfortheseelementsofdamage.”Youshoulduseyourjudgmenttodecideafairamount.The survey then asks the participant to determine an award for pain and
suffering or punitive damages. In the punitive damages scenario, the survey asks:
“Pleasewritedown thedollaramount thatyouwouldawardAndrew forpunitive
damages,asinstructedbythejudge.”Inthepainandsufferingscenario,thesurvey
asks:“PleasewritedownthedollaramountthatyouwouldawardEmmaforherpain
and suffering (past and future) and her loss of capacity for enjoyment of life, as
instructedbythejudge.”
Finally,onceaparticipantentershisaward,thesurveyasksforanoptional
explanation for the amount awarded, aswell as certain demographic information
(discussedfurtherbelow).68
Fortheactivetreatmentconditions,thestemcontainsafourthparagraphthat
containscertaininformationregardingawardsinpriorcomparablecases.Forconditions
68Note,participantswerenotpermittedtoreturntopreviouspages.Therefore,onceaparticipantsubmittedhisawardandproceededtothefollowingpages(requestinganoptionalexplanationordemographicinformation),hewasnotpermittedtoreturntothepagerequestinganawardamount.
176
involvingthelistforminthepunitivedamagesscenario,theparagraphstates:
Additionally,thejudgeinformsyouthatinfiveprevioussimilarcasesjurieshavedeterminedawardsforpunitivedamagesintheamountsof[$____________,$____________,$____________,$____________,and$____________]. The judge indicatesthatthisinformationregardingpriorawardsisintendedasguidanceonly,andthatyoumayuse(ornotuse)theinformationasyouseeappropriate.
Fortherangeform,theparagraphstates:
Additionally,thejudgeinformsyouthatinprevioussimilarcasesjurieshavedetermined awards for punitive damages in amounts ranging from[$____________ to $____________]. The judge indicates that this informationregardingpriorawardsisintendedasguidanceonly,andthatyoumayuse(ornotuse)theinformationasyouseeappropriate.
Andfortheaverageform,theparagraphstates:
Additionally,thejudgeinformsyouthatinprevioussimilarcasesjurieshavedeterminedawardsforpunitivedamagesinamountsaveraging[$____________].Thejudgeindicatesthatthisinformationregardingpriorawardsisintendedasguidanceonly,andthatyoumayuse(ornotuse)theinformationasyouseeappropriate.
Analogousparagraphsareusedforeachlevelofformforthepainandsuffering
scenario.Further,intheactualsurveys,thebracketedmonetaryvaluesabovearefilledin
withprior-awardvalues,wherethevaluesdependonthetreatmentconditiontowhicha
participantisrandomized—andparticularly,onthelevelsofbiasandvariabilityassociated
withthattreatmentcondition.Thesevaluesarediscussedinthefollowingsubsection.
3.4 DeterminingPrior-AwardInformation
Constructingthesurveystobepresentedtoparticipantsinvolveddetermining
numericalvaluesthatwoulddefineeachtreatmentcondition.Forexample,constructinga
surveycorrespondingtoatreatmentconditioninvolvingunbiasedprior-awardinformation
intheformofanaveragerequiredchoosinganawardvaluetopresenttoparticipantsas
177
theaverageofpriorawards.Webeganbyestimatingthe“correct”awardineachscenario,
definedasinTheLogicofCCG,asthemeanofthedistributionofawardsthatwouldresult
frominfinitelyrepeatedadjudications(ofthecontrolcondition)undervarious
conditions.69Onceweestimatedthe“correct”awardineachscenario,weusedtheestimate
todefine,forexample,whatconstitutesbiasedversusunbiasedprior-awardinformation.
Weestimatedthe“correct”awardsusingthemedianofthecontrolconditionineach
scenario.Foranumberofreasons,themedianislikelytoserveasabetterestimatorthan
themean.Forexample,themeanwouldbetooheavilyinfluencedbyafewextremeoutliers
intherelativelysmallsamplesinthecontrolconditions—relativetotheinfinitelyrepeated
adjudicationsthatdeterminethe“correct”awards.Additionally,theawardsinthisstudy
aredeterminedbymockjurors—notactualjuriesinatrialgovernedbyajudge,allofwhich
servetolimittherightskewofthedistributionsofactualawards.70
Importantly,forpurposesofthecurrentstudy,itisnotnecessarytodefineand
estimatea“correct”award.Ourconclusionswouldnotbeweakenedwerewetoanalyze
thetreatmentconditionswithreferencetotheresultsinthecontrolconditiondirectly,
withoutreferencetoa“correct”award.Forexample,withouttakingapositiononhowto
characterizea“correct”award,wecouldinvestigatetheeffectofaparticulartreatment
conditiononmagnitude,relativetothemagnitudeoftheawardinthecontrolcondition.
Afterall,CCGisintendedtoimproveaccuracybyreducingerrorfromdispersion
substantiallymorethanitaddserrorfromdistortion—whatevertheinitial“distortion”
69Seesupra§2.3.
70Seediscussionregardinglimitationsassociatedwiththepresentstudy,infra§5.
178
maybe.Byreferencinga“correct”award,wesimplyassumethattheawarddetermination
isinitiallyundistorted,orunbiased.
Tobesafe,iftheinitialbiasweresufficientlyextreme,wemay,undercertain
conditions,notwanttoreducevariabilityaroundthecentralaward.Butsuchaproblem
wouldrequireanextremeinitialbias,andthereisnoreasontoassumethatsuchabias
exists(evenif,forourpurposes,therewerecausetoassumesomesourceofbiasinthefirst
place).Furthermore,anyassumptionthatsuchabiasexistedwouldbeinconsistentwith
thepositionoftheSupremeCourt,lowercourts,andmanycommentators,thatreducing
randomvariation,withoutmore(e.g.,withoutcausingbias),isbeneficial.Inanyevent,for
purposesofclarityandsimplicity,aswellasforconsistencywithpreviousliterature,we
definethe“correct”awardsasabove,andestimatethemusingthemediansofthecontrol
groupawards.
Thus,toobtaintheseestimates,weconductedapilotstudydesignedidenticallyto
thecontrolstudydescribedabove.WeusedAmazon’sMechanicalTurktorecruitasample
of400pilotparticipants.71Eachparticipantwasrandomlyassignedtooneofthetwolevels
ofscenario(painandsufferingorpunitivedamages),resultinginasampleof200
participantsforeachscenario.Asinthecontrolconditionsinthemainstudy,pilot
participantswereprovidednoprior-awardinformationandwereaskedtodeterminean
awardbasedonthefactpatterntheyreceived.
71Anadditional200participantsweresurveyedforpurposesofaseparateanalysis.Thedatacollectedforthatanalysisarenotrelevanttothispaper,andthereforearenotdiscussed.
179
Assuggestedabove,participantsrandomizedtoreceiveoneoftheactivetreatment
conditionsinthemainstudywereprovidedwithprior-awardinformationasanumerical
summaryintheformofeitheranaverage,arange,oralistofvalues.Todeterminethese
numericalsummariesforeachscenarioandforeachpossiblecombinationofbiasand
variability,weusedtherawdatafromthepilotstudy.Pilotstudydatawerethenexcluded
fromsubsequentanalyses.
Foreachlevelofscenario,theempiricalmedianofawardamountsinthe
correspondingpilotsampleisusedastheunbiasedaverageandthe30thpercentileof
awardamountsisprovidedasthebiasedaverage.72Additionally,foreachlevelofscenario,
the15th,25th,50th,75th,and85thpercentilesofawardamountsinthecorrespondingpilot
sampleareusedastheunbiasedhighvariabilitylist,andthe40th,45th,50th,55th,and60th
percentilesareusedastheunbiasedlowvariabilitylist.Finally,foreachlevelofscenario,
the15thand85thpercentilesoftheawardamountsfromthecorrespondingpilotsample
areusedastheunbiasedhighvariabilityrange,andthe40thand60thpercentilesareusedas
theunbiasedlowvariabilityrange.
Todefinehighvariabilityandlowvariabilityprior-awardinformationinthebiased
conditions,weapplythefollowingprocedure.First,abiasratioiscalculatedastheratioof
the30thpercentiletothemedianwithineachlevelofscenario.Foreachlevelofscenario,we
thenmultiplythevaluesdeterminedfortheunbiasedhighvariabilitylistandunbiasedlow
variabilitylistbythecorrespondingbiasratiotoconstructthebiasedhighvariabilitylist
72Bythedefinitionof“bias,”anyvalueotherthantheempiricalmedianofthecorrespondingpilotsampledistributioncouldbeusedtodefine“biased”prior-awardinformation.Here,the30thpercentilewaschosentoreflectverysubstantial,butnotentirelyunrealistic,court“error”indeterminingasetofpriorawards.
180
andbiasedlowvariabilitylist,respectively.Weapplythesameproceduretoconstructthe
biasedhighvariabilityrangeandbiasedlowvariabilityrangeforeachlevelofscenario.
TableAprovidesthenumericalprior-awardvaluesthatwereprovidedtoparticipantsin
themainstudyineachoftheactivetreatmentconditions.
TableA.PriorAwardInformationProvidedintheVariousActiveTreatmentConditionsScenario Biasand
VariabilityForm Prior-AwardInformation73
PainandSuffering
UnbiasedLowVariability
Average $2mRange $1.12mto$4.7mList $1.12m,$2m,$2m,$3m,$4.7m
UnbiasedHighVariability
Average $2mRange $200kto$15mList $200k,$500k,$2m,$10m,$15m
BiasedLowVariability
Average $1mRange $560kto$2.35mList $560k,$1m,$1m,$1.5m,$2.35m
BiasedHighVariability
Average $1mRange $100kto$7.5mList $100k,$250k,$1m,$5m,$7.5m
PunitiveDamages
UnbiasedLowVariability
Average $1mRange $500kto$1mList $500k,$500k,$1m,$1m,$1m
UnbiasedHighVariability
Average $1mRange $10kto$10mList $10k,$52.5k,$1m,$5m,$10m
BiasedLowVariability
Average $100kRange $50kto$100kList $50k,$50k,$100k,$100k,$100k
BiasedHighVariability
Average $100kRange $1kto$1mList $1k,$5.25k,$100k,$500k,$1m
73Weuse“m”todenotemillionsand“k”todenotethousands.
181
3.5 AssessingandCorrectingCovariateBalance
Duetoresourceandprivacyconstraints,covariatedatawereunavailablepriorto
thestartoftheexperiment.Inparticular,dataonninecovariates—age,sex,ethnicity,
education,employmentstatus,maritalstatus,householdincome,residentialcommunity
type,andpoliticalaffiliation—werecollecteduponaparticipant’scompletionofthesurvey.
Itisdesirabletohavereasonablecovariatebalanceacrossalltreatmentconditions.
However,withninecovariates,therewasahighprobabilityofobservingimbalanceonat
leastonecovariateamongthe22conditions.Thiswassignificant,becauseimbalancecould
preventusfromknowingwhetheranyobservedeffectswereattributabletothe
interventionortotheimbalance.Therefore,oncethedatawerecollected,andbefore
proceedingtothegeneralanalysisphaseoftheexperiment,wesoughttoexamineand
correctforanysubstantialcovariateimbalanceproducedbytheobservedrandomization.
But,toavoiddata“dredging”andensurethatcovariatebalancewouldbecorrectedinan
objectivemanner,weanalyzedthecovariatedatainaso-called“secondarydesignphase.”
Specifically,weanalyzedthedataintwophases.First,weremovedalloutcomedataand
consideredonlycovariatedata.Priortoaccessingthecovariatedata,however,wedesigned
andfinalizedproceduresforassessingcovariatebalanceandforaddressingany
imbalances.74
Toassesscovariatebalanceacrossthe22treatmentgroups,weexamineddataon
theninedemographicvariablesmeasuredinthesurvey.Additionally,weexaminedtwo
74DesignandAnalysisProtocolonfilewithauthors.Iftheobservedcovariatebalancewerenotsuitable,wewouldhaveproceededbyborrowingmethods,suchas“trimming”basedonpropensityscores,establishedforcausalinferencewithobservationaldata.
182
variablesconstructedusingsurveymetadataregardingenrollmenttimes—timeofdayand
dayofweekofsurveyenrollment—tocheckforsystematicdifferencesinparticipantsbased
onstudyenrollmenttimesthatmayinfluenceoverallcovariatebalanceandvalidateour
assumptionthatparticipantsenrolledinthestudyrandomly.75
Theobservedrandomizationproducedtreatmentgroupsthatwereapproximately
equalinsize,withthesmallesttreatmentgroupcontaining245participantsandthelargest
groupcontaining260participants.Becausethesamplesizeofeachtreatmentgroupwas
approximatelyequalacrossthe22groups,weappliednoweightingbytreatmentgroup
sizewhenassessingcovariatebalance.
WeanalyzedcovariatebalanceusingPearson’schi-squaredtest.When
implementingthistestinpractice,itispreferable,forpurposesofstatisticalvalidity,to
havefiveormore(expected)observationsineachcellofthecovariatecontingencytable.76
Ifthiscriterionisnotsatisfied,itiscommonpracticetocombine,wheresensible,
neighboringlevelsofthetable.Wethusfollowedthisprocedureforlevelsofcovariatesthat
containedlessthan5observationspercell,inordertoensurethateachcellwouldcontain
asufficientnumberofobservations.Inparticular,wecombinedcertainneighboringlevels
75Wealsoconsideredathirdvariablerelatedtoenrollmenttimes—weekend—whichindicateswhethereachparticipantenrolledduringaweekend(definedasanytimeofdayonSaturdayorSunday).Nosignificantimbalancesonthisvariablewereidentified,andbecausethisindicatorisadeterministicfunctionofdayofweek,whichisalsoshowntobebalancedacrossall22treatmentgroups,weexcludedweekendfromfurtheranalyses.
76SeegenerallyWilliamG.Cochran,Theχ2TestofGoodnessofFit,23(3)THEANNALSOFMATHEM.STAT.315(1952).
183
withineachofthefollowingcovariates:age,ethnicity,education,employment,income,and
residentialcommunitytype.77
Independentchi-squaredtestsrevealednostatistically“significant”differences
amongthe22treatmentgroupsinthefrequencydistributionofeachofthenine
demographicvariables(includingage(p=0.15),sex(p=0.55),ethnicity(p=0.82),
education(p=0.33),employment(p=0.87),maritalstatus(p=0.76),income(p=0.34),
residentialcommunitytype(p=0.34),andpoliticalaffiliation(p=0.71)).78Similarly,no
significantdifferencesamongtreatmentgroupswereidentifiedforeitherofthe
enrollment-timevariables(includingdayofweek(p≈1)andtimeofday(p≈1)).The
observedp-valueforthechi-squaredtestoneachoftheenrollment-timevariables
supportsourassumptionthatparticipantsenrolledinthestudyrandomlyandprovides
evidencethattherandomizationschemeperformedasintended.
77Forage,weaggregatedlevelsforagesabove61tocreateone“Over61”level.Forethnicity,participantswhomarked“AmericanIndianorAlaskaNative”wereaggregatedwithparticipantsmarkingthevalue,“Other.”Foreducation,participantswhomarked“None,”“Somehighschool,”or“Highschoolgraduate”wereaggregatedintothelevelof“Highschoolorless,”andparticipantswhomarked“Master’sdegree,”“Doctoratedegree,”“Lawdegree,”or“Medicaldegree”wereaggregatedintothelevel,“Master’sdegreeorhigher.”Foremploymentstatus,participantswhomarked“Retired”wereaggregatedintothelevel,“Other.”Forincome,levels“$100,000-$150,000”and“Over$150,000”wereaggregatedintothelevel,“Over$100,000.”Finally,forresidentialcommunitytype,participantswhomarked“Suburban”or“Don’tknow”wereaggregatedintothelevel“Suburbanoruncertain.”Additionally,forthecovariatesex,weobserved20participantswhomarkedtheresponse“Other”(averagingoneorfewerobservationspertreatmentgroup).Becausethereisnoclearwaytorecodetheseobservationsintoeitherthe“Male”or“Female”levels,weexcludedtheseparticipantsfromsubsequentanalyses.Iftherearesystematicdifferencesinresponsepatternsforthesubpopulationthatidentifiesas“Other,”theexclusionoftheseobservationsmaylimitourabilitytogeneralizeresultsfromthisstudytothissubpopulation.However,weperformedpost-hocanalysestoevaluatetheimpactofexcludingtheseparticipantsfromthestudyandtounderstandthegeneralizabilityofourresults.Oneparticipantwhoidentifiedas“Other”wasremovedinthedatacleaningprocess(describedbelow);andcorrelationanalysisoftheremaining19observationsindicatesnosignificantassociationsbetweenidentificationas“Other”andawardamount,bothwithinandacrosslevelsofscenario.Thissuggeststhatremovalofthese19participantsfromouranalysishasnoconsiderableimplicationsonthegeneralizabilityofthestudy.
78Wepresenthereraw,unadjustedp-values.
184
Tofurtherconfirmsuitablebalanceforrelevantcomparisongroups,weperformed
pairwisecomparisonstoevaluatedifferencesinfrequencydistributionsoneachcovariate
foreachofthe pairsofdistincttreatmentgroupsusingFisher’sexacttest.79To
correctformultiplecomparisons,weappliedtheprocedureproposedbyBenjaminiand
Hochberg(1995),hereinreferredtoasthe“Benjamini-Hochbergprocedure,”tocontrolthe
falsediscoveryrate(FDR).80Afteradjustmentformultiplecomparisons,nosignificant
differencesbetweenpairsoftreatmentgroupswereidentifiedonanyoftheeleven
variablestested.
Wealsoperformedtestsfortwo-wayinteractionsamongtheninedemographic
variablesandthetwoenrollment-timevariables.Theseinteractioneffectscanhelpusto
betterunderstandtheobservedsampleandevaluatehowinferencefromthisstudy
generalizestothepopulationofinterest.Again,weemployedtheBenjamini-Hochberg
proceduretoadjustformultiplecomparisons.Afteradjustment,ofthe tests
performed,46interactionswereidentifiedasstatistically“significant”attheoveralllevelof
α=0.05.81Suchcorrelationsarenotsurprising(forexample,agemaycorrelatewith
experienceand/orresponsibility,andthuswithemployment;dayofweekmaycorrelate
79Wealsoperformedcomparisonsacrossaggregationsoftreatmentgroupscorrespondingtothe60effectsofinterestdefinedinourprimaryanalysisandfoundsuitablebalanceforeachaggregation.
80YoavBenjamini&YosiHochberg,ControllingtheFalseDiscoveryRate:APracticalandPowerfulApproachtoMultipleTesting,57(1)J.OFTHEROYALSTAT.SOC.SERIESB(STAT.METHODOLOGY)289.
81Forexample,sexsignificantlycorrelateswithmaritalstatus,agesignificantlycorrelateswithemploymentstatus,anddayofweeksignificantlycorrelateswithtimeofday.
222
!
"#
$
%&= 231
112
!
"#
$
%&= 55
185
withlighterworkschedulesandthuswithtimeofdayofsurveyenrollment).Ofgreater
interestaretheinteractionsofthedemographicvariableswiththeenrollment-time
variables,sinceextremecorrelationsofthistypemayhaveimplicationsregardingthe
assignmentmechanism.82Inthesetests,significantinteractionswereidentifiedfortimeof
dayandthedemographicvariablessex,income,andmaritalstatus.However,becausewe
observedsuitablebalanceoneachoftheelevenvariablesacrosseachofthe22treatment
groups,therewasnoreasontobelievethattheidentifiedinteractionsmayhaveintroduced
confoundingintotherandomizationorhavenegativeimplicationswithrespecttothe
validityofthestudy.Theseinteractioneffectssimplyservetocharacterizethepopulation
representedbyoursampleandmaybefurtherconsideredinpost-hocanalysesand/or
whenattemptingtogeneralizetheresultsofthestudy.
Insummary,ouranalysisofthecovariatedataindicatedthatsuitablebalanceonall
demographicvariablesandenrollment-timevariablesacrossthe22treatmentgroupswas
achievedbytheobservedrandomization.Therefore,weproceededtotheanalysisphaseof
theexperimentwithoutapplyinganycorrectionsoradjustmentstoimprovebalance.
3.6 CausalInferenceforFactorialEffects
Theanalysisofdatafromfactorialexperimentsoftenreliesonageneralizedlinear
modelframework(i.e.,analysisofvariance(ANOVA)).However,asdiscussedin2K
FactorialDesigns,theseapproacheshavedrawbacksthatcanimpedetheabilitytomake
82Forexample,iffemalesenrolledinthestudyexclusivelyonMondays,thenumberofrandomizationsthatarepossibletoobserveusingourrandomizationschemewoulddecrease,havingimplicationsforouranalysisforpurposesofmakingvalidinferences.
186
causalconclusionsabouttheexperimentalfactors.83Wethereforebaseouranalysesand
estimationofcausaleffectsonthepotentialoutcomesframeworkofNeyman,84often
referredtoastheRubinCausalModel(RCM).85Wefollowthebasicnotationand
philosophyofestimationin2KFactorialDesigns,whichdevelopedatheoreticalframework
forcausalinferencefromfactorialdesignsusingthepotentialoutcomesmodel.
UndertheRCM,eachunit,i.e.,eachparticipant,inthisexperimenthas22“potential
outcomes,”oneforeachpossibletreatmentcombination.Forexample,aparticipantmay
haveawarded$4millionhadhebeenrandomizedtothepunitivedamagesscenarioofthe
controlcondition,$2millionhadhebeenrandomizedtotheunbiased,lowvariability,
average,punitivedamagestreatmentcondition,$1millionhadhebeenrandomizedtothe
biased,lowvariability,average,punitivedamagestreatmentcondition,andsoonandso
forthforall22possibletreatmentcombinations.TheRCMframescausalinferenceasa
missing-dataproblem:becausewecanobserveonlyonepotentialoutcomeforeachunit—
theonetowhichtheunitwasinfactassigned—wedonotknow,andthereforemust
estimate,thevaluesoftheunobservedpotentialoutcomestomakecausalconclusions.86
83Forexample,onedrawbackofthelinearmodelframework,assuggestedin2KFactorialDesigns,istherequirementthatthecausalestimandsbedefinedasparametersoftheprobabilitydistributionoftheobservedresponse.Tothecontrary,ourresultsdonotrelyondistributionalassumptions.See2KFactorialDesigns.
84SeeJerzyNeyman,OntheApplicationofProbabilityTheorytoAgriculturalExperiments.EssayonPrinciples.Section9.,RocznikiNaukRolniczychTomX[inPolish]:translatedin5StatisticalScience465(1923).
85SeePaulW.Holland,StatisticsandCausalInference,81(396)J.oftheAm.Stat.Ass’n.945(1986).
86Seegenerallyid.;Rubin,supranote60;2KFactorialDesigns.
187
Ingeneral,afactorial“maineffect”ofanexperimentalfactorforeachunitisthe
differenceinafunction(e.g.,themean)ofthepotentialoutcomesbetweenasubsetofthe
potentialoutcomescorrespondingtoonelevelofthefactorandtheremaining(or,herein,a
subsetof)potentialoutcomes.87Forexample,theunit-levelmaineffectofunbiasedprior-
awardinformationrelativetobiasedpriorawardinformationisthedifferencebetweena
function(suchasthemean)ofthepotentialoutcomesassociatedwiththesubsetof
treatmentcombinationsthatincludeunbiasedprior-awardinformation(thatis,the
outcomesthatwouldoccurhadtheunitbeenassignedtothesetreatmentcombinations)
andthesamefunctionofthepotentialoutcomesassociatedwiththesubsetoftreatment
combinationsthatincludebiasedprior-awardinformation(thatis,theoutcomesthat
wouldoccurhadtheunitbeenassignedtothesetreatmentcombinations).
87Notationally,asin2KFactorialDesigns,letKdenotethenumberofexperimentalfactors,whichareindexedbyk,eachwithpklevels,suchthatthereare treatmentcombinations.Letzj,forj=1,…J,denoteoneparticulartreatmentcombination,definedbyaK-dimensionalvector,wherethekthelementindicatesthelevelofthekthfactor,fork=1,…,K.LetZdenotethesetofallpossibletreatmentcombinations.Further,letNdenotethetotalsamplesize,indexedbyi=1,…,N.AndletYi(z)denotethepotentialoutcomeoftheithunitunderexposuretotreatmentz.2KFactorialDesignsat730.LetYi=(Yi(1),…,Yi(J))bethevectorofallpotentialoutcomesforuniti.DefinegastheJ-1vectors,indexedbyj=1,…,J-1,suchthatgjisavectorofdimensionJwithvaluesthatindicatethelevelsoffactorscorrespondingtopotentialoutcomes.Id.Forexample,ifwerefertoscenarioasfactor1,theng1isavectorofeleven-1’sfollowedbyeleven+1’s,indicatingthatthefirsteleventreatmentcombinationsz1,…,z11havethescenariofactorsettopainandsufferingandthefollowingelevencombinationshavethescenariofactorsettopunitivedamages.Usingthisnotation,thefactorialmaineffectoftreatmentcombinationjcomparedtoallothertreatmentcombinationsforuniticanbedefinedgenerallyas
τ ij =1
#{gj =1}Yi
gj=1∑ −
1#{gj ≠1}
Yigj≠1∑ where #{gj =1} denotesthenumberofelementsofgjthatare
equaltoone.Similarly,thefactorialeffectoftreatmentcombinationjrelativetotreatmentcombinationj*for
uniticanbedefinedasτ ij, j*=
1#{gj =1}
Yi −gj=1∑ 1
#{gj*=1}
Yigj*=1∑ .Factorialeffectsforeachlevelpkofeach
factorkaredefinedbyaggregatingovertreatmentcombinationsthathavefactorksettothatlevel.Thesedefinitionsaresimilarlyextendedtosubsetsoftreatmentcombinations.Seeid.
J = p1 ×...× pk
188
Two-way,three-way,andfour-way“interactioneffects”canbedefinedsimilarly.For
example,theunit-leveleffectofunbiasedhighvariabilityprior-awardinformation,relative
tounbiasedlowvariabilityprior-awardinformation,canbedefinedasthedifference
betweenthemeanofthepotentialoutcomesassociatedwiththesubsetoftreatment
combinationsthatincludeunbiasedhighvariabilityprior-awardinformationandthemean
ofthepotentialoutcomesassociatedwiththesubsetoftreatmentcombinationsthat
includeunbiasedlowvariabilityprior-awardinformation.88
Notethatwedonottest“across”levelsofscenario.Thatis,forpurposesofanalysis,
wetreatthepainandsufferingscenarioandthepunitivedamagesscenarioasseparate
studies;andallcomparisons,correspondingtoeffectsofinterest,aremadewithinlevelsof
scenario—thatis,withinthepainandsufferingscenarioorthepunitivedamagesscenario.
Thus,wesometimesreferto,e.g.,theeffectofbiasorvariability,withinalevelofscenario,
asa“maineffect.”
3.7 EstimandsandEstimators
Theprimaryobjectivesoftheexperimentaretoassessthefinite-populationeffects
ofprior-awardinformation,fordifferentlevelsofbias,variability,andform,onthe
magnitude,spread,andaccuracyofresultingawardvalues,whereaccuracyisdefinedasthe
88Throughoutthestudy,wemakethestableunittreatmentvalueassumption(SUTVA).Thismeans1)thatthepotentialoutcomeofaunitdependsonlyonitsownassignment,andnotontheassignmentsofotherunits,and2)thatthereareno“hiddenversions”oftreatment.2KFactorialDesignsat730.Forthisexperiment,wehavenoreasontobelievethattherewasinterferenceacrossunitsbecausethepopulationfromwhichwerecruitedparticipantsconsistsofmanydistinctusersfromacrosstheUnitedStates.Further,notethatMechanicalTurkrequiredthateachsurveyparticipanthaveauniqueIPaddress.Similarly,becausewecarefullycontrolledtheadministrationofallsurveys,wearearguablyjustifiedinassumingthattherewerenohiddenversionsoftreatment.Weassumethateachparticipantreadthesurveytheywereassignedinitsentirety.
189
proximityoftheawardstothe“correct”awardintermsofbothbiasandvariance.These
objectivesmotivateourchoiceof“estimands,”thequantitiesweareinterestedin
estimating.Wedefinethreegeneralestimands—oneformagnitude,oneforspread,andone
foraccuracy—andcorresponding“estimators,”functionsofthedatathatweuseto
estimatethequantitiesofinterest,i.e.,theestimands.
Magnitudecanbecapturedquantitativelyusingameasureofcentraltendency,such
asthemeanormedian.Becausetheoutcomeismonetaryandknowntobepositively
skewed,forpurposesofanalysiswedefinemagnitudeasthemeanofthelogarithm-
transformedawardamounts.Althoughthisdefinitioninvolvesanumberofdrawbacks,
discussedbelow,itreducestheeffectoftherightskewanditallowsustocapturerelative,
ratherthanabsolute,differences.89Ontheotherhand,wedefinespreadastheinterquartile
range(IQR)oftheoutcome,whichismorerobusttooutliersthanthevariance;andwe
defineaccuracyastheinverseofthemean-squarederror(MSE),whichisequaltothesum
ofthevarianceandthesquaredbias.Thus,tocalculateaccuracy,weestablishanumerical
rulefordefiningthe“correct”award,reflectingourestimatorforthe“correct”award
discussedsupra§3.4.Specifically,withineachlevelofscenario,themedianamount
awardedinthecontrolgroupofthemainstudyisusedasthe“correct”award.
Wethusdefinethefinite-populationfactorialeffectofeachexperimentalfactorand
interactionsbetweenfactorsonthemagnitudeofawardvaluesasthedifferencebetween
89Forexample,thedifferencebetween$0and$100shouldarguablybeinterpreteddifferentlythanthedifferencebetween$1,000,000and$1,000,100.Althoughcapturingrelativedifferencesisimportant,thisdefinitionmaynotbeidealorappropriateinthepresentcontext.Wediscussthis,andalternativedefinitions,infra§4.4.
190
themeanofthelogarithm-transformedpotentialoutcomesassociatedwitheachofthe
comparisongroups,respectively.Weapplythisdefinitiontoallsuchcomparisongroups,
whetherformaineffects,ortwo-way,three-way,orfour-wayinteractioneffects.For
example,inthepainandsufferingscenario,theeffectonmagnitudeoflowvariability
unbiasedprior-awardinformation,relativetohighvariabilityunbiasedprior-award
information,isthedifferencebetweenthemeanofthelogarithm-transformedpotential
outcomesassociatedwiththeformerandthemeanofthelogarithm-transformedpotential
outcomesassociatedwiththelatter.
Weestimatetheseeffects(sincetheestimandisafunctionofunknownquantities)
byusingthecorrespondingsetsofobserveddata.90Wedefinethefinite-populationfactorial
effectonthespreadofawardvaluesastheinterquartilerange(IQR)—definedasthe
differencebetweenthe75thpercentileandthe25thpercentile—ofthepotentialoutcomes
associatedwitheachofthecomparisongroups,respectively.Weestimatethiseffectusing
thecorrespondingsetsofobserveddata.91
90Moreformally,wedefinethefinite-populationfactorialeffectoftreatmentcombinationjcomparedtoall
othertreatmentcombinationsonthemagnitudeofawardvaluesasτ mag⋅ j =
1#{gj =1}
!Ygj=1∑ −
1#{gj ≠1}
!Ygj≠1∑ ,
where denotesthemeanofthelogarithm-transformedpotentialoutcomes.We
estimatethisquantityusingtheestimator τ̂ mag⋅ j =
1#{gj =1}
!Y obs
gj=1∑ −
1#{gj ≠1}
!Y obs
gj≠1∑ .Asabove,these
definitions,aswellasthedefinitionsforspreadandaccuracybelow,aresimilarlyextendedtocomparisonsofparticulartreatmentcombinationsorsubsetsoftreatmentcombinationstootherparticulartreatmentcombinationsorsubsetsoftreatmentcombinations.Seesupranote87.Seegenerally2KFactorialDesigns.
91Wedefinethefinite-populationfactorialeffectoftreatmentcombinationjcomparedtoallothertreatmentcombinationsonthespreadofawardvaluesas
!Y =1N
log(Yi +1)i=1
N
∑
191
Finally,wedefinethefinitepopulationfactorialeffectontheerrorofaward
amounts,theinverseoftheaccuracyofawardamounts—andthusontheaccuracyof
awardamountsitself—asthedifferencebetweentheMSEs,definedasthemeanofthe
squareddifferencesbetweeneachvalueandthe“correct”value,ofthepotentialoutcomes
associatedwitheachcomparisongroup,respectively.Here,again,weestimatetheeffecton
accuracyusingtheobserveddatacorrespondingtothecomparisongroups.92
Usingthefactorial-effectestimatorsweestimateaneffectbycomputingthevalues
ofmagnitude,spread,oraccuracyforeachofthetreatmentcombinationsinvolvingthe
factor(orcombinationoffactors)ofinterest,andthenseparatelyaveragingovereachof
τ spread⋅ j =
1#{gj =1}
(q0.75(Y )− q0.25(Y ))−gj=1∑ 1
#{gj ≠1}(q0.75(Y )− q0.25(Y ))
gj≠1∑ ,where denotesthesth
quantileoftheempiricaldistributionof .Thiseffectisestimatedusingtheestimator
τ̂ spread⋅ j =
1#{gj =1}
(q0.75(Y obs )− q0.25(Y obs ))−gj=1∑ 1
#{gj ≠1}(q0.75(Y obs )− q0.25(Y obs ))
gj≠1∑ .Seegenerally2K
FactorialDesigns.
92Wedefinethefinite-populationfactorialeffectoftreatmentcombinationjcomparedtoallothertreatment
combinationsontheaccuracyofawardamountsasτ acc⋅ j =
1#{gj =1}
(Y −α)2gj=1∑ −
1#{gj ≠1}
(Y −α)2gj≠1∑ ,
whereαisthe“correct”award,whichtakesonadifferentvalueforeachscenario.Ifz1representsthecontrolconditioninthepainandsufferingscenarioandz12representsthecontrolconditioninthepunitivedamagesscenario,wehave ,astheestimatorofthe“correct”awardforthepainandsuffering
scenarioand astheestimatorofthe“correct”awardforthepunitivedamagesscenario.Wethenestimatethefactorialeffectoftreatmentcombinationjontheaccuracyofawardamountsforthepainandsufferinglevelofscenariousingtheestimator
τ̂ acc,PS⋅ j =
1#{gPS
j =1}(Y obs −α̂ PS )2
gj=1∑ −
1#{gPS
j ≠1}(Y obs −α̂ PS )2
gj≠1∑ ,andforthepunitivedamageslevelof
scenariousingtheestimator τ̂ acc,PD⋅ j =
1#{gPD
j =1}(Y obs −α̂ PD )2
gj=1∑ −
1#{gPD
j ≠1}(Y obs −α̂ PD )2
gj≠1∑ ,wheregjPSand
gjPDarevectorswithvaluesindicatingthelevelofeachfactorforeachpotentialoutcomewhenthescenariofactorissettopainandsufferingorpunitivedamages,respectively.Seegenerallyid.
qs (Y )
Y
α̂ PS =med(Yiobs (z1))
α̂ PD =med(Yiobs (z12 ))
192
thetreatmentcombinationswiththesamelevelofthefactor(orcombinationoffactors).
Forexample,forthemaineffectofbiasonmagnitudewithinthepainandsufferingscenario,
we:1)calculatethemagnitudeofawardamountsseparatelyforeachofthe10treatment
combinationsreceivingeitherbiasedorunbiasedpriorawardinformationinthepainand
sufferingscenariousingthemeanofthelogarithm-transformedvalues;2)averagethe
valuesfromstep(1)acrossthe5treatmentcombinationsreceivingbiasedinformation,and
separatelyaveragethevaluesfromstep(1)acrossthe5treatmentcombinationsreceiving
unbiasedinformation;and3)calculatethedifferenceoftheaveragesobtainedinstep(2).
Alsonotethattheestimandsandestimatorsdefinedinthissubsectionapplytomain
effects,aswellasalltwo-way,three-way,andfour-wayinteractioneffects.
3.8 AnalysisProcedure
Oncewecalculatetheestimatesofthefactorialeffectsusingobserveddata,weare
interestedinunderstandingthe“statisticalsignificance”oftheestimatedeffects,whichcan
beinterpretedasanindicatorofhowunlikelytheobserveddifferencesbetweentreatment
groupswouldbeundercertainhypothesizedeffects.93TheRCMallowssuchinference
usingtheNeymanian(1923,1990)perspective,Fisherianperspective(1925,1935),orthe
Bayesianperspective.94
Becausetheestimatorforcapturing,e.g.,thespreadofawardvaluesisnotan
unbiasedestimatorofitscorrespondingestimand,andforotherreasons,wedecidednotto
93Rubin,supranote60.
94SeeDonaldB.Rubin,BayesianInferenceforCausalEffects:TheRoleofRandomization,6(1)THEANN.OFSTATIST.34(1978).
193
useNeyman’smethod.Instead,weadopttheFisherianapproach,anduserandomization
teststoevaluateFisher’ssharpnullhypothesisof“nounit-leveltreatmenteffects.”For
example,totestwhethertheestimateofthemaineffectofeachfactoronmagnitude,
spread,andaccuracyofawardvaluesis“significant,”weassumeFisher’s“sharpnull”—a
hypothesizedeffect,suchasa“sharpnull”of“zerotreatmenteffect”—inordertoimpute
themissingpotentialoutcomesforeachunitandrepeatedlycalculatethevalueofa
specifiedteststatisticunderdifferentpossibletreatmentassignments.Then,giventhe
distributionofeachteststatistic,wecalculateapproximateFisher“exactp-values”(FEPs)
toindicatethestatistical“significance”ofeffects.Wecanalsousethisprocedureto
constructFisherexactintervalsforeachestimate.
OneofthemajoradvantagesoftheFisherianapproachtoinference,asopposedtoa
model-basedorBayesianapproach,isthatitdoesnotrequireanyassumptionsaboutthe
underlyingdistributionofthedata.Thus,randomizationtestscanbeconstructedand
appliedforanyteststatistic,regardlesswhetheritsdistributionisknown.
Duetolimitedcomputationalresources,wefollowthecommonapproachof
constructingrandomizationdistributionsusingsamplesofthepossiblerandomizations,
ratherthancomputingallpossiblerandomizationsoftheN=5480participantsintothe22
treatmentconditions.
Duetothenumberofexperimentalfactorsandquestionsofinterestinthisstudy,to
estimateandevaluatethestatistical“significance”ofeachoftheeffectsofinterestrequires
numeroushypothesistests.Whentestingmanyhypotheses,theprobabilityofidentifying
falseeffectsincreaseswiththenumberoftestsperformed.Toadjustforthisincreased
194
probabilityoffalseidentifications,itisappropriatetoapplyanadjustment,or“correction,”
toallestimatedp-values.95However,applicationofsuchanadjustmentacrossalarge
numberoftestsgenerallydecreasesthepowerofthestudytoidentifyresultsthatare
actually“significant.”
Toaddressthisissue,wedivideourtestsintoaprimaryanalysiscategoryanda
secondaryanalysiscategory,correspondingtotheeffectsofprimaryandsecondary
interest,respectively,andapplycorrectionsformultiplecomparisonsseparatelywithin
eachcategory.Thetestsintheprimarycategoryrelatetothestudy’sprimaryquestionsof
interest.Thetestsinthesecondarycategoryrelateto1)questionsthatareofsecondary
interest,2)effectsofinterestthatmayprovideconfirmatoryorsupportiveevidenceof
resultsidentifiedintheprimaryanalysiscategory,orthatmayanswerquestionsthat
followfromresultsidentifiedintheprimaryanalysiscategory,or3)exploratoryanalysis.
Becausewearemostinterestedinunderstandingprimaryeffectswithineachlevel
ofscenario,intheprimaryanalysiscategorywetreatasindividualexperiments1)all
treatmentconditionsreceivingthepainandsufferinglevelofscenario,and2)alltreatment
conditionsreceivingthepunitivedamageslevelofscenario.Thus,intheprimaryanalysis
category,wetesteacheffectofinterestwithineachofthetwolevelsofscenarioandapplya
correctionformultiplecomparisonsseparatelywithineach.Inparticular,wetestten
effectswithineachofthetwolevelsofscenariooneachofthethreeoutcomesofinterest
(magnitude,spread,andaccuracy),foratotalof10x2x3=60primaryhypothesistests.96
95SeeBenjamini&Hochberg,supranote80.
96Intheprimaryanalysiscategory,wetestthefollowingtentestswithineachlevelofscenario:1)theeffectofunbiasedprior-awardinformationrelativetonoprior-awardinformation(control);2)theeffectof
195
Alladditionalhypothesistestsareperformedinthesecondaryanalysiscategory,
includingtestsforthemaineffectsofformandvariability,andadditionaltwo-way,three-
way,andfour-wayinteractioneffectsamongbias,variability,andform.Inbothanalysis
categories,wecorrectformultiplecomparisonsaswedidintheSecondaryDesignPhasein
theanalysisphaseofthisstudy,usingtheBenjamini-Hochbergproceduretocontrolthe
false-discoveryrate(FDR).97
Ourprocedureforestimatingfactorialeffectsandcarryingoutinferenceforeach,
whichincludescomputingp-valuestotestthenullhypothesesof“notreatmenteffect”and
constructingintervalsfortheestimatedeffects,isoutlinedbelow.
Estimatingeffects.Foreachestimandofinterest,weusetheobserveddatato
computethevalueofthecorrespondingestimator.Becausetheestimandsaredefinedas
differencesbetweentreatmentgroups,foreachestimate,weareinterestedintestingthe
nullhypothesisof“nodifferencebetweengroups”—thatis,weareinterestedintestingthe
unbiasedprior-awardinformationrelativetonoprior-awardinformation(control)whenprior-awardinformationislowvariability;3)theeffectofunbiasedprior-awardinformationrelativetonoprior-awardinformation(control)whenprior-awardinformationishighvariability;4)theeffectofbiasedprior-awardinformationrelativetonoprior-awardinformation(control);5)theeffectofbiasedprior-awardinformationrelativetonoprior-awardinformation(control)whenprior-awardinformationislowvariability;6)theeffectofbiasedprior-awardinformationrelativetonoprior-awardinformation(control)whenprior-awardinformationishighvariability;7)theeffectofbiasedprior-awardinformationrelativetounbiasedprior-awardinformationwhenprior-awardinformationishighvariability;8)theeffectofbiasedprior-awardinformationrelativetounbiasedprior-awardinformationwhenprior-awardinformationislowvariability;9)theeffectoflowvariabilityprior-awardinformationrelativetohighvariabilityprior-awardinformationwhenprior-awardinformationisunbiased;10)theeffectoflowvariabilityprior-awardinformationrelativetohighvariabilityprior-awardinformationwhenprior-awardinformationisbiased.
97Thisprocedurelimitstheexpectedproportionoftestsfalselyidentifiedas“significant”relativetothetotalnumberoftestsidentifiedas“significant.”Itisawell-acceptedapproachtocorrectingformultiplecomparisonswhileoftenresultinginmorepowerthanmethodscontrollingthefamilywiseerrorrate(FWER),suchastheBonferronicorrectionandtheensembleadjustedp-valueapproach.SeeMariaT.Kimeletal.,TheFalseDiscoveryRateforMultipleTestinginFactorialExperiments,50(1)TECHNOMETRICS32(2012).
196
hypothesisthatthetruedifferencebetweengroupsiszero.Therefore,foreachhypothesis
test,weusethecorrespondingestimatortodefinetheteststatisticforourrandomization
test.
Constructingrandomizationdistributions.Foreacheffectofinterest,weassume
thesharpnullhypothesisof“nounit-leveltreatmenteffect”toimputemissingpotential
outcomesforeachparticipant.WethengenerateasampleofNsim=250,000possible
randomizationsoftheNparticipants.98Foreachofthese250,000possiblerandomizations,
werecomputethevalueoftheteststatisticunderthe(hypothetical)randomization.The
resultingdistributionisreferredtoasthe“randomizationdistribution”oftheteststatistic.
Testinghypotheses.WeapproximateFEPsforeachhypothesisbycalculatingthe
proportionofvaluesintherandomizationdistributionthatwereequaltoormoreextreme
thantheobservedteststatistic.Allestimatedp-valuesareadjustedformultiple
comparisonsusingtheBenjamini-HochbergproceduretocontroltheFDR.Aftercorrection,
weconsiderestimatedp-valuesoflessthanα=0.05tobe“statisticallysignificant.”
Significantp-valuessuggestthatthereissubstantialevidencewithinthedataagainstthe
nullhypothesisofnotreatmenteffect.
Constructingintervals.Foreachfactorialeffect,wecangeneratea95%Fisher
intervalbycalculatingasequenceofraw,unadjustedp-valuescorrespondingtoanull
hypothesisotherthanthehypothesisof“zerotreatmenteffect,”andthenidentifythe
98WechooseNsim=250,000toensureprecisionoftheestimatedp-value.ProfessorsImbensandRubinshowthat,forasampleofthissize,thestandarderrorofeachestimatedp-valuewillbelessthan0.001.SeeGuidoW.Imbens&DonaldB.Rubin,CausalInferenceforStatistics,Social,andBiomedicalSciences(2015).
197
hypothesizedvaluesthatresultinp-valuesequaltoorlargerthan0.05.Forallestimates
weassumeaconstantadditivetreatmenteffect.99
4. Results
Beforediscussingourresults,itisimportanttonotethat,priortoaccessingany
data,wedraftedandfinalizedanExperimentalDesignandAnalysisProtocolthatdetailed
thedesignofthestudyandallaspectsofourintendedanalysis.100Weensuredthatwe
wouldnothaveaccesstothedatabyaskingathird-partyadministratortolockouraccess
ontherelevantdatabase,andtounlockthedata,wheninstructed,onlyuponour
circulation(andpostingtoSSRN)ofafinalizedExperimentalDesignandAnalysisProtocol.
Inthissection,wereportandinterpretourresults.Forpurposesofclarityandease
ofinterpretation,wedividethesectionintotopics,reflectingcategoriesofeffectsof
interest.Foreachtopic,wereportourresultsandaccompanyinginterpretation.Then,in
thefollowingsection,theConclusion,wetieourfindingstogether,relatethemtothemodel
introducedinTheLogicofCCG,anddiscusslimitations.
Asapreliminarymatter,itisimportanttorealizethatouranalysisinvolved
approximately250hypothesistests,reflectingmaineffectsandinteractionsamongthe
variousfactors.Therecanbenumerousteststhatspeaktoaparticulareffect,andsome
resultsmayseemunsupportiveof,oreveninconsistentwith,others.Ourgeneralapproach
tointerpretingthedataisasfollows:First,weexaminethecomparisonthatmostdirectly
99Note,becauseweusethelogarithmtransformationforestimatingfactorialeffectsonmagnitude,weinterprettheresultingintervalsfortheseestimatesasmultiplicativeeffects.
100Onfilewiththeauthors.
198
speakstoaneffectofinterest.Second,weexamineothercomparisonsthatspeaktothe
effectlessdirectly.Third,ifwefindsupportfortheeffectinstep(1)andsupportforthe
effectinstep(2),wegenerallyinterpretthedataasevidencingastrongeffect.Ifwefind
supportfortheeffectinstep(1)butanabsenceofevidencefororagainsttheeffectinstep
(2),wegenerallyinterpretthedataasevidencinganeffect,unlessthereisaparticular
reasontobelieveotherwise.Ifwefindsupportfortheeffectinstep(1)butevidence
againsttheeffectinstep(2),weexaminetheinconsistencythataroseinstep(2).Ifour
examinationrevealsastraightforwardexplanationthatdefusestheinconsistency,we
interpretthedataasevidencinganeffect.Iftheexaminationfailstoreveala
straightforwardexplanation,weinterpretthedataasnotevidencinganeffect;andwe
examinetheresultsforanalternativeexplanation.
4.1 TheData
Thedatacanbedividedintotwodatasets:oneforthepunitivedamagesscenarioand
oneforthepainandsufferingscenario.101Thereareapproximately240-250observationsin
eachtreatmentlevelforeachscenario.Theawarddeterminationsareextremelyvariable.
Awardsrangefrom$0to$15billioninthepunitivedamagesscenario,witha99thpercentile
101Priortoanalyzingthedata,weappliedaninitial“datacleaning”proceduretoensuredataquality.First,toensurethevalidityofresponses(e.g.,thattheyoriginatedfromregisteredMechanicalTurkuserswhometourinclusioncriteria),weexcluded23participantswhoenteredanincorrectpaymentcodethatwasintendedtoindicate,forpurposesofreceivingpayment,thattheparticipantcompletedthesurvey.Second,weexcludedfourparticipantswhoprovidedawardamountsthatweredeemed“nonsensical”byoursoftware.Becauseonlyaverysmallnumberofparticipantswereexcludedfromtheinitialsampleof5,500participants,andtherewasnoevidencesuggestinganyresultingsystematicdistortion,weexcludedtheseparticipantswithoutapplyingadvancedmissingdatatechniques.Additionally,asdiscussedintheMethodologySection,participantswhomarked“Other”fortheirsexwereexcluded,duetoourinabilitytosensiblymergethatcategorywithoneoftheothercategoriesofsexforpurposesoftestingforcovariatebalance.Afterenforcingtheseexclusioncriteria,ourfinalsamplesizeisN=5,458.
199
of$50million,and$0to$1Quadrillion(1×1015 )inthepainandsufferingscenario,witha
99thpercentileof$100million.
Toaddressextremeoutliers,we“truncate”thedatainthepainandsufferingdataset
(inwhichtheproblemisparticularlyacute)atthe99thpercentile.Thismeansthatany
awardsabove$100millionarerecodedto$100million.Thisisimportant,sinceextreme
outlierscancausespuriousresultsthataredominatedbychanceratherthantrueeffects.102
Weappliedthisapproachtothepunitivedamagesdataalso,butfindthatthetruncation
methodinthatscenariohasnoeffectonourfindings,becausetheoutliersinthepunitive
damagesscenarioarefarlessextremeinsizeandeffect.
Thus,unlessstatedotherwise,theresultswereportandinterpretbelowreflectthe
rawdatasetforthepunitivedamagesscenarioandthetruncateddatasetforthepainand
sufferingscenario.Wesometimesusethetruncateddataforthepunitivedamagesscenario
ortherawdataforthepainandsufferingscenario,butonlyforillustrativepurposes—i.e.,
tomakeapointregardingthosedatainparticularor,incertaininstances,forpurposesof
creatingeasily-interpretabledisplays.Insuchinstances,westateclearlythatweareusing
thesealternativedatasets.Below,wealsoexaminetheeffectsofprior-awardinformation
102Notethat,indesigningtheexperiment,weweresensitivetothefactthat,whilemanystudiesuseliberalmethodsforaddressingoutliers,extremevaluesareofparticularinterestinthecurrentstudy.Asaresult,weattemptedtoavoidtheuseofsuchtechniques.However,becausethestudyinvolvesmonetaryvaluesthatparticipantschosefromtheirimagination,theoutliersinthisstudy—andparticularlythoseinthepainandsufferingscenario—wereparticularlyextreme,exceedingevenourexpectations.Uponobservingthemagnitudeoftheawards,weunderstoodthatnotaddressingtheoutliersmayresultinspuriouseffectsandotheranomaliesthatwouldresultfromrandomnessratherthanatrueeffect.Wethereforedecidedtoaddressoutliersinthepainandsufferingscenariousingtheconservativemethoddescribedinthetext.Weproceedusingthetruncateddataset.Notethatsuchextremeawards(andlikelysomethatarefarlessextreme)arehighlyunlikelyinpractice,andwould,inanyevent,beaddressedbythecourtsusingthedeviceofremittitur.
200
onoutliersseparately,aswellastherobustnessofourresultsusinganalternative
truncationthreshold.103Summarystatisticsforeachscenario(rawandtruncated)are
providedinTableB.
TableB.SummaryStatisticsforSample(N=5,458)
4.2 EffectofPrior-AwardInformationonAccuracy
Thedataprovidestrongevidencethatprior-awardinformationreduceserrorand
improvesaccuracy.Inbothlevelsofscenario,andacrossalllevelsofbiasandvariability,
andtheirinteractions,prior-awardinformationhasasignificantpositiveeffectonaccuracy.
FigureV.1illustratestheapproximaterandomizationdistributionsandobservedtest
statisticsforthehypothesistestsof“notreatmenteffect”ineachscenario;andeffectson
error(theinverseofaccuracy)withineachlevelofscenarioaresummarizedinTableCand
103Seeinfra§4.6.
104Weexcludefromthissummaryofrawpainandsufferingdatathreeextremevaluesthataregreaterthanorequalto$100billion.Theseobservationsareremovedfromthissummarysolelyfordescriptivepurposes.
StatisticPunitiveDamages(Raw)
PunitiveDamages
(Truncatedat99thpercentile($50million))
PainandSuffering(Raw104)
PainandSuffering
(Truncatedat99thpercentile($100million))
SampleSize 2751 2751 2704 2707
Mean(millions) $18.3 $2.3 $23.8 $6.7
Median(millions)
$0.5 $0.5 $3.0 $3.0
StandardDeviation(millions)
$397.3 $6.4 $396.0 $14.0
IQR(millions) $0.9 $0.9 $3.5 $3.5
201
FigureV.2below.Thedatasetforthepunitivedamagesscenario,inadditiontothedataset
forthepainandsufferingscenario,istruncatedinthissubsectionforpurposesof
interpretabilityandillustration(althoughourfindingswouldnotchangewerewetouse
thedatawithouttruncation).InTableC,Fisherintervalsareprovidedforthedifferencein
errorbetweeneachtreatmentlevelandcontrol,wheretheMSEinthecontrolgroupforthe
punitivedamagesscenariois$146trillionandtheMSEinthecontrolgroupforthepainand
sufferingscenariois$492trillion.
FigureV.1.Randomizationdistributionforeffectoftreatment(anyprior-awardinformation)versuscontrol(noprior-awardinformation)onaccuracyforpunitivedamagesdata(left)andpainandsufferingdata(right),eachtruncatedatits99thpercentile($50millionand$100million,respectively).Redlinesshowobservedteststatistics.
202
TableC.EffectsonError
Effect
PunitiveDamages(truncatedat99thpercentile($50million))
PainandSuffering(truncatedat99thpercentile($100million))
MSE(trillionsof
dollars)
Differencefromcontrol(MSE=146)(trillionsofdollars)
(95%FisherInterval)
Unadjustedp-value105
MSE(trillionsof
dollars)
Differencefromcontrol(MSE=492)(trillionsofdollars)(95%FisherInterval)
Unadjustedp-value
Treatment(anyprior-awardinformation)
33 -114(-141,-80)
0.000*** 192 -300(-423,-156)
0.008**
Unbiasedprior-awardinformation
56 -103(-132,-70)
0.000*** 221 -271(-404,-122)
0.002***
Unbiasedlowvariabilityprior-awardinformation
19 -127(-161,-91)
0.000*** 230 -262(-415,-101)
0.008**
Unbiasedhighvariabilityprior-awardinformation
57 -89(-122,-52)
0.001** 261 -231(-381,-71)
0.013*
Biasedprior-awardinformation
22 -124(-153,-91)
0.000*** 163 -329(-460,-183)
0.000***
Biasedlowvariabilityprior-awardinformation
24 -123(-157,-86)
0.000*** 131 -361(-515,-195)
0.000***
Biasedhighvariabilityprior-awardinformation
30 -116(-151,-79)
0.000*** 109 -383(-532,-221)
0.001***
105Throughoutthissection,starsindicatestatisticalsignificanceaftercorrectionformultiplecomparisons.Inparticular,***denotesstatisticalsignificanceattheα=0.001level,**denotessignificanceattheα=0.01level,and*denotessignificanceattheα=0.05level.
203
FigureV.2.Observedmeansquarederror(MSE)(intrillions)fordifferenttreatmentcombinationsforpunitivedamages(left)andpainandsuffering(right).DottedlinesshowMSEforcontrolgroup,andstarsindicatestatisticalsignificance(aftercorrectionformultiplecomparisons)ofthedifferenceinMSEbetweeneachtreatmentcombinationandcontrol.
Asdiscussedabove,prior-awardinformationisexpectedtocausethepossible
introductionoferrorintheformofdistortion,orbias,butalsoreduceerrorbyreducingthe
dispersionofawards.Inbothlevelsofscenario,thebeneficialeffectondispersion
dominatesanydistortionaryeffectonthesizeoftheaward,causinganimprovementin
accuracy.Inbothlevelsofscenario,thereisasignificantpositiveeffectonaccuracy
overall—comparingallactivetreatmentconditionscombined(i.e.,anytreatment
combinationthatinvolvesanyprior-awardinformation)tothecontrolconditionofno
prior-awardinformation(p<0.000***forpunitivedamagesandp=0.008**forpainand
suffering).Furthermore,prior-awardinformationimprovesaccuracywhethertheprior-
awardinformationisunbiasedlowvariability(p<0.000***forpunitivedamagesand
p=0.008**forpainandsuffering),unbiasedhighvariability(p=0.001**forpunitivedamages
andp=0.013*forpainandsuffering),biasedlowvariability(p<0.000***forpunitive
204
damagesandp<0.000***forpainandsuffering),orbiasedhighvariability(p<0.000***for
punitivedamagesandp=0.001**forpainandsuffering).106
Moreover,toconfirmthatourresultsholdwithouttheinfluenceofthemore-
extremevalues,weexaminefourimportanteffectsusingthepunitivedamagesandpain
andsufferingdatatruncatedatthe90thpercentile—i.e.,truncatedat$5millionforpunitive
damagesand$10millionforpainandsuffering.Usingthesedata,weneverthelessobserve
asignificantimprovementinaccuracycausedbyunbiasedlowvariability(p<0.000***for
punitivedamagesandp<0.000***forpainandsuffering)andbiasedlowvariability
(p<0.000***forpunitivedamagesandp<0.000***forpainandsuffering)prior-award
informationforbothlevelsofscenario.Ourresultsfortheseeffectsaresummarizedin
TableDandFigureV.3below.
106Weanalyzetheeffectofformonaccuracyaswell.Thedataprovideevidencethatprior-awardinformationgenerallyimprovesaccuracyregardlessofform—i.e.,regardlesswhethersuchinformationispresentedasanaverage,list,orrangeofpriorawards.
205
TableD.EffectsonErrorWhenTruncatingatthe90thPercentile
Effect
PunitiveDamages(truncatedat$5million)
PainandSuffering(truncatedat$10million)
MSE(trillions
ofdollars)
Differencefromcontrol(MSE=4.29)
(trillionsofdollars)
(95%FisherInterval)
Unadjustedp-value
MSE(trillions
ofdollars)
Differencefromcontrol(MSE=16.4)
(trillionsofdollars)(95%FisherInterval)
Unadjustedp-value
Unbiasedlowvariabilityprior-awardinformation
1.39 -2.89(-3.7,-2.1)
0.000*** 11.3 -5.19(-7.5,-3.1)
0.000***
Biasedlowvariabilityprior-awardinformation
1.37 -2.92(-3.8,-2.2)
0.000*** 6.57 -9.9(-12.2,-7.7)
0.000***
206
FigureV.3.Observedmeansquarederror(MSE)(intrillionsofdollars)forunbiasedlowvariabilityandbiasedlowvariabilityconditionsforpunitivedamagesdata(left)andpainandsufferingdata(right),whentruncatedatthe90thpercentileineachscenario.DottedlinesshowMSEforcontrolgroup,andstarsindicatestatisticalsignificance(aftercorrectionformultiplecomparisons)ofthedifferenceinMSEbetweeneachtreatmentcombinationandcontrol.
OurresultsthusprovidestrongempiricalsupportfortheconclusioninTheLogicof
CCG,thatprior-awardinformationimprovesaccuracyundervariousconditionsofbias,
variability,andform.
4.3 EffectofPrior-AwardInformationonSpread
Theeffectsofprior-awardinformationonaccuracyevidenceeffectsonthe
dispersionofawardsaswell.Specifically,becauseaccuracyisdefinedusingMSE,whichcan
beseparatedintobiasandvariance,andbecauseprior-awardinformationcannotreduce
bias(ordistortion),weknowthatanyimprovementinaccuracyisduetoareductionin
variance.However,weseparatelytesttheeffectofprior-awardinformationonspread,
whichwedefinedifferently,usingtheIQRratherthanvariance.Understandingtheeffectof
207
prior-awardinformationonspread,inadditiontoitseffectsonaccuracy,permitsamore
nuancedunderstandingofthedata.
TheIQRis,inasense,lesssensitivetodifferencesinrandomvariation.Forexample,
changingavalueatthe95thpercentilefrom$1millionto$50millionwouldnotaffect
spread.Butspreadprovidesspecificinformation—thedifferencebetweenthe75th
percentileandthe25thpercentiles—thatmaybeobscuredinothermeasuresofrandom
variation.
Thedataprovidestrongevidencethatprior-awardinformationreducesspread.In
thepunitivedamagesscenario,ourcomparisonofallactivetreatmentconditions
(combined)tothecontrolconditionindicatesthat,overall,prior-awardinformationcauses
asignificantreductioninspread(p<0.000***).Furthermore,wefindthatbothunbiased
prior-awardinformationandbiasedprior-awardinformationcauseareductioninspread
(p=0.02*forunbiasedandp<0.000***forbiased).107
Inthepainandsufferingscenario,wedetectasignificantreductioninspreadcaused
bybiasedprior-awardinformation(p<0.000***),butnosignificanteffectcausedby
unbiasedprior-awardinformation.Thislatterresultisnotverysurprising,becausethe
rangeofthepriorawardsinthepainandsufferingscenario—andparticularlythehigh
107Note,wefindthattheaveragelevelofformtendstohaveagreaterdownwardimpactonspreadrelativetotheotherlevelsofform.Thismaybeinterpretedasresultingfromtheparticipants’perceptionthatthereisnovariabilityintheprior-awards,sincetheywereprovidedonlyasinglenumber.Alternatively,theparticipantscouldhaveinterpretedtheaverageformasprovidinglessinformationandtherefore“deservingof”lessinfluence.Participantssimplydidnotknowwhethertheaveragereflected,forexample,fivepriorawardsofidenticalvaluesorfivehighlyscatteredpriorawards.Onbalance,theyseemtohave“interpreted”(likelyimplicitlyratherthanactively)theinformationasreflectingawardsoflowervariability.
208
variabilityprior-awardinformation—isfarlargerthanthecontrolgroupIQR.108This
causesspreadtoremainunchanged(i.e.,withoutsignificanteffect),andeventoincreasein
responsetohighvariabilityprior-awardinformation,notwithstandinganoverallreduction
inrandomvariation,asreflectedintheeffectsofunbiasedprior-awardinformationon
accuracyinthepainandsufferingscenario.109Effectsonspreadwithineachlevelofscenario
aresummarizedinTableEbelow.FisherintervalsareprovidedinTableEforthe
differenceinspreadbetweeneachtreatmentlevelandcontrol,wherethecontrolgroupfor
punitivedamageshasaspreadof$2,900,000andthecontrolgroupforpainandsuffering
hasaspreadof$4,500,000.TableFsummarizessupportfromthedatafortheexplanation
above,andinnote109,reflectingouranalysisregardingtherelationshipbetween1)the
108Thereasonsforthisaretwofold:1)thepercentileschosenfordeterminingtherangeofvaluesofunbiasedhighvariabilitypriorawardsarethe15thand85thpercentiles,substantiallywiderthanthe25thand75thpercentiles;and2)thereisgreaterspreadinthepilotstudydatathaninthecontrolgroupdata,causedby“choppiness”inthedataorsamplingvariationresultingingreaterdispersioninthepilotstudyawards.
109Unbiasedhighvariabilityandunbiasedlowvariabilityprior-awardsinthepainandsufferingscenariorangefrom$200,000to$15millionandfrom$1.12millionto$4.7million,respectively,comparedtothe25thand75thpercentilesofthepainandsufferingcontrolgroupawards,whichare$50,000and$5million,respectively.Thisexplanationiscorroboratedbyourresultsinthepunitivedamagesscenario,where,althoughspreaddecreasesinresponsetounbiasedandbiasedprior-awardinformation(separatelyandcombined),anddecreasesinresponsetounbiasedlowvariability,biasedlowvariability,andbiasedhighvariabilityprior-awardinformation,itincreasesinresponsetounbiasedhighvariabilityprior-awardinformation.Thismakessense,because,aswiththepainandsufferingscenario,unbiasedhighvariabilitypriorawardsrangeinvaluefrom$10,000to$10million,fargreaterthanthecontrolgroup25thand75thpercentiles,$100,000and$3million,respectively.(Comparethistotheunbiasedlowvariabilitypriorawards,whichrangeonlyfrom$500,000to$1million,wellwithintherangeofcontrolgroup25thand75thpercentiles.)Thisexplanationisfurthersupportedbypreviousfindingsthatinformingjurorsofadamagescapmaycauseanupwardeffectonawardamountsanddispersion.SeeSaks,etal.,supranote20,at249-53.Notethatsuchaneffectisnotobservedforbiasedprior-awardinformation,sincetheawardsinthosetreatmentconditionsarefarlessvariable(andhavefarlowerranges)thantheawardsintheunbiasedtreatmentconditions.Wethusobserveasignificantreductioninoverallspreadcausedbybiasedprior-awardinformationinbothlevelsofscenario(evendespitetheabsenceofadetectedreductioninmagnitudeinthepainandsufferingscenario(discussedinfurtherdetailinfra)inresponsetobiasedprior-awardinformation).
209
rangeofthepriorawardsprovidedtoparticipantsrelativetothecontrolgroupIQR,and2)
theeffectoftheprior-awardinformationonspread.
210
TableE.EffectsonSpread
Effect
PunitiveDamages PainandSuffering
Spread(IQR)
Differencefromcontrol(IQR=
2,900,000)(95%FisherInterval)
Unadjustedp-value
Spread(IQR)
Differencefromcontrol(IQR=
4,500,000)(95%FisherInterval)
Unadjustedp-value
Treatment $1,430,000 -$1,470,000(-$1,620,000,-$1,070,000)
0.000*** $4,978,000 $478,000(-$610,000,$2,400,000)
0.603
Unbiasedprior-awardinformation
$2,351,000 -$549,000(-$749,000,-$70,000)
0.018* $6,000,000 $1,500,000(-$72,000,$3,510,000)
0.104
Unbiasedlow
variabilityprior-awardinformation
$427,500 -$2,472,500(-$2,720,000,-$1,980,000)
0.000*** $2,750,000 $-1,750,000(-$3,250,000,$320,000)
0.109
Unbiasedhigh
variabilityprior-awardinformation
$4,825,000 $1,925,000($1,675,000,$2,420,000)
0.000*** $10,750,000 $6,250,000($4,750,000,$8,310,000)
0.000***
Biasedprior-awardinformation
$509,000 -$2,391,000(-$2,580,000,-$1,920,000)
0.000*** $3,955,000 -$545,000(-$1,650,000,$1,430,000)
0.524
Biasedlowvariabilityprior-awardinformation
$172,500 -$2,727,500(-$2,970,000,-$2,280,000)
0.000*** $1,887,500 -$2,612,500(-$4,110,000,-$566,000)
0.017*
Biasedhighvariabilityprior-awardinformation
$900,000 -$2,000,000(-$2,280,000,-$1,490,000)
0.000*** $6,000,000 $1,500,000($0,
$3,560,000)
0.152
211
TableF.RatiosofRangetoIQRandEffectsonSpread PunitiveDamages PainandSuffering
Rangeofawardspresented
25thpercentile–75th
percentileofcontrol
Ratioof
rangeto
IQR110
Effectonspread
Rangeofawardspresented
25thpercentile–
75thpercentileofcontrol
RatioofrangetoIQR
Effectonspread
Unbiasedhigh
variability
$10,000-$10million
$100,000-$3
million344% +
$200,000-$15million
$500,000-$5million 329% +
Unbiasedlow
variability
$500,000-$1million
$100,000-$3
million17% -
$1.12million-$4.7million
$500,000-$5million 80% 0
Biasedhigh
variability
$1,000-$1
million
$100,000-$3
million34% -
$100,000-$7.5million
$500,000-$5million 164% 0
Biasedlow
variability
$50,000-
$100,000
$100,000-$3
million2% -
$560,000-$2.35million
$500,000-$5million 40% -
Toconfirmourinterpretationofourfindingsregardingspread,andtotestits
robustnesstoalternativetruncationthresholdsandmeasuresofdispersion,wetestthe
effectsofunbiasedprior-awardinformationonthestandarddeviationofaward
determinationsusingthedataforeachscenariotruncatedatthe90thpercentile.Thesetests
providesubstantialsupportforourfindingsandinterpretationabove.Specifically,inboth
levelsofscenario,weobservethatunbiasedprior-awardinformationsignificantlyreduces
thestandarddeviationofawardsrelativetocontrol(p<0.000***forpunitivedamagesand
110CalculatedaslengthofrangedividedbylengthofIQR.
212
p<0.000***forpainandsuffering).Furthermore,inbothlevelsofscenario,weobservethat
unbiasedlowvariabilityprior-awardinformationsignificantlyreducesstandarddeviation
relativetocontrol(p<0.000***forpunitivedamagesandp<0.000***forpainandsuffering),
whereasunbiasedhighvariabilitypriorawardinformationhasnosignificanteffecton
standarddeviationrelativetocontrol(asexpected,duetotherelatively-largedispersionof
unbiasedhighvariabilitypriorawards).
Oneimplicationofourresultswithrespecttospreadisthat,althoughcourtsneed
notbeconcernedthatprior-awardinformationwillreduceoveralldispersionand
accuracy,courtsshouldbecognizantofthepossibilitythatprovidingpriorawardsthat
haveveryhighvariabilitymay,undercertainconditions,increasespread—evenwhile
reducingdispersionoverall—andthushaveamitigatingeffectonthebenefitsofprior-
awardinformationforaccuracy.
Significantly,inadditiontotheeffectsonspread,thesetestsconfirmourbelief
regardingtherobustnessoftheeffectofprior-awardinformationonaccuracy.Specifically,
notwithstandinganydetrimentalconsequencesofthesizeabledispersionofthehigh
variabilitypriorawards(andunbiasedhighvariabilitypriorawardsinparticular),we
observethatprior-awardinformationhasasignificantlypositiveeffectonaccuracyacross
theboard.
4.4 EffectofPrior-AwardInformationonMagnitude
Ourinterestisintestingwhetherunbiasedandbiasedprior-awardinformation(as
wellasinteractionswiththevariabilityofpriorawards)causeanydistortion(or“bias”)in
thesizeofawards.PursuanttoourAnalysisProtocol,webeginbyexaminingtheeffecton
213
magnitude,usingthemeanofthelog-transformeddataforeachscenarioandwithinlevels
ofbiasandvariability.Weobserve,however,thatthismeasuremayresultinsomewhat
misleadingresultsforthecurrentstudy.
Themeanofthelog-transformeddataisacommonly-usedmeasurefortesting
magnitudewithright-skeweddata.Thereasonthatitispopularforright-skeweddatais
thatit“pullsin”extremedatapointsmorethanit“pullsin”moderatedatapoints.Under
certainconditions,however,usingthemeanofthelog-transformeddatacandistortthe
signofanobservedeffect.Thiscanoccur,asitdidinthecurrentstudy—and,likely,
becauseparticipantschosevaluesfromtheirimagination—whensomeawardsare
sufficientlyextremethattheobservedeffectofthenon-transformeddataisdominatedby
theeffectoftheextremeawards.Therefore,whenthoseawardsare“pulledin”more
substantiallythanmoremoderateawards,theobservedeffectisreversedorotherwise
distorted.
Now,arguably,themeanofthelog-transformeddataisamoreappropriatemeasure
withwhichtotestmagnitude,sinceitmitigatestheotherwise-overwhelminginfluenceof
outliers.Inthisstudy,however,thisislikelynotthecase.Specifically,althoughweobserve
anincreaseinthemagnitudeofawardsresultingfromunbiasedprior-awardinformation
(forbothpainandsufferingandpunitivedamages),mosttestsinvolvingothermeasuresof
awardsizeresultinnosignificanteffect.Forexample,usingthemeanresultsinno
significanteffectofunbiasedprior-awardinformationonawardsizeinthepainand
sufferingscenario,andanegativeeffectofunbiasedprior-awardinformationonawardsize
inthepunitivedamagesscenario(andnoeffectifthepunitivedamagesdataistruncatedat
214
the99thpercentile).Itispossiblethattheseeffectsareheavilyinfluencedbyextreme
values;but,arguably,theinfluenceofextremevaluesissignificantinthisstudy—
particularlywherethedatasetsaretruncatedatthe99thpercentile,sincethesedatasets
alreadyexcludethemostextremedatapoints.
Furthermore,forbothpunitivedamagesandpainandsuffering,weobservedno
differencesbetweenthemedianofthecontrolgroupawardsandthemedianoftheawards
inconditionsinvolvingunbiasedprior-awardinformation.Asopposedtothemeanofthe
unloggeddata,thismeasureexcludestheeffectofextremevalues.Wealsotestedtheeffect
ofunbiasedprior-awardinformationonawardsizeusingasameasureofsizethemeanof
awardsinthedatatruncatedatthe90thpercentile,findingnosignificanteffectforpunitive
damagesandapositiveeffectforpainandsuffering.Wesummarizetheeffectsofunbiased
prior-awardinformationonawardsizeunderalternativemeasurementsinTableGbelow.
TableG.Unbiasedvs.Control:AlternativeMeasurementsandCorrespondingEffects
onAwardSize PunitiveDamages PainandSuffering
Logmean Median Mean
Mean(truncatedat90th
percentile)
Logmean Median Mean
Mean(truncatedat
90thpercentile)
Unbiasedversuscontrol Positive 0 Negative 0 Positive 0 0 Positive
Similarly,forbiasedprior-awardinformationinthepainandsufferingscenario,
usingeitherthemeanormedianoftheunloggeddatarevealsnosignificanteffecton
215
magnitude,relativetoawardsinthecontrolcondition,whereasusingthemeanofthe
loggeddataindicatesapositiveeffect,relativetoawardsinthecontrolcondition(p=0.02*).
Thus,ourresultsregardingtheeffectofunbiasedprior-awardinformationwith
respecttoawardsizecanbedescribedasinconclusive.Although,usingthemeanofthelog-
transformeddata,wedetectapositiveeffectofunbiasedprior-awardinformationon
magnitude(p<0.000***forpunitivedamagesandp<0.000***forpainandsuffering),atbest,
thetestsareverysensitivetothemeasureused,and,atworst,thelog-transformcauses
dramaticdistortions.Inanyevent,usingothercommonmeasuresofsize,suchasthe
median,wedetectnosignificantdifferencebetweenthesizeofawardsinthecontrol
conditionandthesizeofawardsintheunbiasedconditions.
Ofcourse,wecanattempttointerpretthisbreakdownofeffects.Onewayof
understandingitisasfollows:unbiasedprior-awardinformationhasnosignificanteffect
onthesizeofawards,inthesensethatthecentralawardisnotaffected.Forexample,inthe
punitivedamagesscenario,themedianofawardsinboththecontrolconditionandacross
theunbiasedconditionsis$1million.Ontheotherhand,unbiasedprior-awardinformation
hasnoeffectorasignificantnegativeeffectonawardsizewhentheeffectsofextreme
awardsareconsidered.Thisiscorroboratedbyourexploratoryanalysisregarding
outliers,111andissignificantinthecurrentstudy,sinceextremeawards,aswellasrandom
variationgenerally,istheproblemthatprior-awardinformationseekstoaddress.Finally,
unbiasedprior-awardinformationmaycausegreaterawardsize,inthesensethatthe
111Seeinfra§4.6.
216
awardsintheunbiasedconditionsaregreaterwhentheeffectofmoreextremeawardsis
excludedbuttheeffectofsomelevelofextremenessisincluded.Onepossibleexplanation
forthiseffectisthattheobserveddetrimentaleffectofthesizeabledispersionofhigh
variabilityprior-awardinformationonspreadmayalsocausesomepositiveeffecton
awardsize,duetothelopsidednatureofthehighvariabilitypriorawards,whichare
boundedfrombelowat$0butunboundedfromaboveandrightskewed.Inanyevent,this
lattereffectisinteresting,butnotveryrobust,sincetheresultsreverttoinsignificance
whenweuse(unlogged)datatruncatedatthe99thpercentiletoexcludeextremeoutliers,
andmixedresultswhenweuse(unlogged)datatruncatedatthe90thpercentile.
Additionally,inlinewithourexpectations,forbiasedprior-awardinformationinthe
punitivedamagesscenario,thedataevidenceasignificantnegativeeffectonmagnitude
(measuredusingthemeanoftheloggeddata)(p<0.000***).Thisresultisconsistentwith
theeffectdirectionobservedusingothermeasuresofawardsize,suchasthemedianor
mean.Further,forpunitivedamages,theoveralleffectofprior-awardinformationon
magnitude,relativetoawardsinthecontrolcondition,isnotsignificant.Similarly,we
observenosignificanteffectonawardsizewhenmeasuredusingthemeanofthelogged
dataorthemedian,andadownwardeffect(inlinewithourexpectations,duetotheeffect
ofbiasedprior-awardinformation)whenawardsizeismeasuredusingthemeanoftheraw
data(p<0.000***).
Finally,regardlesswhetherprior-awardinformationaffectsawardsize,inalllevels
ofbiasandvariability,andforbothlevelsofscenario,weobservethatprior-award
informationimprovesaccuracy.
217
4.5 EffectofLowVariabilityPrior-AwardInformationRelativetoHigh
VariabilityPrior-AwardInformation
Wefindstrongevidence,inlinewithourexpectations,thatlowvariabilityprior-
awardinformationismoreinfluentialthanhighvariabilityprior-awardinformation.
First,forbothlevelsofscenario,thedataindicatethatlowvariabilityprior-award
informationcausesareductioninspread(p<0.000***forpunitivedamagesandp<0.000***
forpainandsuffering)andareductioninmagnitude(p<0.000***forpunitivedamagesand
p<0.000***forpainandsuffering),relativetohighvariabilityprior-awardinformation.
PursuanttothemodelinTheLogicofCCG,lowvariabilityprior-awardinformationprovides
moreinformationthanhighvariabilityprior-awardinformation,112andthushasagreater
influenceonawarddeterminations.This“influence”translatestogreaterimpactsonspread
andmagnitude.
Thus,forbothlevelsofscenario,unbiasedlowvariabilityprior-awardinformation,
relativetounbiasedhighvariabilityprior-awardinformation,hasnosignificanteffecton
magnitudeandasignificantnegativeeffectonspread(p<0.000***forpainandsufferingand
p<0.0000.***forpunitivedamages).Theseresultsareinlinewithourexpectations:
unbiasedprior-awardinformationisexpectedtohavenosignificanteffectonmagnitude,
whetheritislowvariabilityorhighvariability,andprior-awardinformationisexpectedto
haveagreaternegativeimpactonspreadifitislowvariabilitythanifitishighvariability.
112Seesupra§2.3.
218
Moreover,forbothlevelsofscenario,biasedlowvariabilityprior-awardinformation,
relativetobiasedhighvariabilityprior-awardinformation,hasasignificantnegativeeffect
onbothmagnitude(p<0.000***forpainandsufferingandp<0.000***forpunitivedamages)
andspread(p<0.000***forpainandsufferingandp=0.003**forpunitivedamages).These
resultsarealsoinlinewithourexpectations.Specifically,becausetheprior-award
informationisbiased,therearetwoeffects—lowvariabilityprior-awardinformationhas
greaterinfluencethanhighvariabilityprior-awardinformation,andthereforebotha
greaterdistortionary,or“biasing,”effectonmagnitude(here,anegativeeffect),anda
greater“narrowing”effectonspread.Ourresultsregardingtheeffectsoflowvariability
prior-awardinformationrelativetohighvariabilityprior-awardinformationare
summarizedinTableHbelow.
TableH.LowVariabilityvs.HighVariabilityPrior-AwardInformation
PunitiveDamages(Raw)PainandSuffering(truncatedat99th
percentile($100million))
OutcomeObservedtest
statistic
Unadjustedp-value
Observedteststatistic
Unadjustedp-value
Lowvariabilityvs.highvariability
MSE(intrillions) 100,692 0.825 -4.50 0.930
Spread -$2,562,000 0.000*** -$6,056,250 0.000***Magnitude -0.38 0.000*** -0.35 0.000***
Lowvariabilityunbiasedvs.highvariabilityunbiased
MSE(intrillions) -4,544 0.827 -31 0.758
Spread -$4,397,500 0.000*** -$8,000,000 0.000***Magnitude -0.09 0.591 -0.18 0.165
Lowvariabilitybiasedvs.highvariabilitybiased
MSE(intrillions) 205,928 0.493 22 0.803
Spread -$727,500 0.004** -$4,112,500 0.000***Magnitude -0.67 0.000*** -0.52 0.000***
219
Note,apossibleargumentagainstthisinterpretationisthattheresultsobservedcan
beexplainedbytheeffectofhighvariabilityonspreadratherthantheeffectoflow
variabilityontheinfluenceoftheprior-awardinformation.Specifically,asdiscussedabove,
itispossiblethatthehighvariabilityprior-awardinformationcausesanobservedincrease
inspread,sincetherangeofthehighvariabilitypriorawardsisgreaterthantheIQR.Itis
thereforepossiblethattheobservedeffecthereresultsfromremovinghighvariability
awardsandthusremovingtheupwardeffectonspread.Indeed,suchaneffectcouldalso
explainanobserveddecreaseinspreadcausedbyunbiasedlowvariabilityprior-award
informationrelativetounbiasedhighvariabilityprior-awardinformation.Inotherwords,it
ispossibletoarguethattheobservedreductioninspreadhasnothingtodowiththe
influenceoflowvariability,versushighvariability,prior-awardinformation,butrather,that
itiscausedmerelybyremovingtheupwardeffectonspreadcausedbythesizeable
dispersionofthehighvariabilitypriorawards.
Itismoredifficult,however,toapplythisexplanationtotheeffectsofbiasedlow
variabilityprior-awardinformation,relativetobiasedhighvariabilityprior-award
information,withrespecttospreadandmagnitude.Incontrasttounbiasedprior-award
information,itisunlikelythateitherbiasedlowvariabilityprior-awardinformationor
biasedhighvariabilityprior-awardinformationwouldcauseanincreaseinspread,relative
tothecontrolcondition.Indeed,inbothlevelsofscenario,neitherbiasedlowvariability
prior-awardinformationnorbiasedhighvariabilityprior-awardinformationhassuchan
effect.Thisisbecausethevariabilityofsuchinformationisreducedsubstantiallybythe
220
biasratio,113leadingtomutedlevelsofvariabilityforlowvariabilityandhighvariability
prior-awardinformationinthebiasedconditionsrelativetotheircounterpartsinthe
unbiasedconditions.
Furthermore,rememberthatbiasedlowvariabilityprior-awardinformationdoes
notinvolvepriorawardsthatareofloweramountthanbiasedhighvariabilityprior-award
information;rather,itonlyhaslowervariability.Thebiasedlowvariabilityprior-award
information(rangingfrom$50,000to$100,000)iscompletelycontainedwithintherange
ofvaluesinthebiasedhighvariabilityprior-awardinformation(rangingfrom$1,000to$1
million).
Thus,theobservedsignificantnegativeeffectsofbiasedlowvariabilityprior-award
information,relativetobiasedhighvariabilityprior-awardinformation,onspreadand
magnitude,andwithinbothlevelsofscenario,providestrongevidencethatlowvariability
prior-awardinformationhasgreaterinfluence—i.e.,ismoreimpactful—onaward
determinationsthanhighvariabilityprior-awardinformation.Thisfindingprovides
supportforthemodelassumptioninTheLogicofCCG,thattheinfluenceofprior-award
informationisproportionaltotheinverseofthevariabilityoftheawards.
4.6 TheEffectofPrior-AwardInformationonOutliers
Inourexploratoryanalysis,weexaminetheeffectofprior-awardinformationon
“outliers,”whichwedefineasawardsatorabovethe99thpercentile($50millioninthe
punitivedamagesscenarioand$100millioninthepainandsufferingscenario).
113Seesupra§3.
221
Inthecontrolgroupofthepunitivedamagesscenario,therearethirteen
observationsoutof249(5.2%)above$50million,whereasinthetentreatmentarmsof
thepunitivedamagesscenario,therearetwenty-threeobservationsoutof2502(0.9%)
above$50million,or,onaverage,approximatelytwoobservations(23/10=2.3)above$50
millionper249observations.Thisrepresentsasignificantreductioninoutliers( χ 21 = 29.2,
p<0.000**).Furthermore,inthefiveunbiasedtreatmentarmsinthepunitivedamages
scenario,therearefourteenobservationsoutof1257(1.1%)above$50million,or,on
average,approximatelythree(14/5=2.8)above$50millionper249observations.This
alsorepresentsasignificantreductioninoutliers( χ 21 =17.6, p<0.000***).
Inthecontrolgroupoftheuntruncateddatasetforthepainandsufferingscenario,
therearetenobservationsoutof244(4.1%)above$100million,whereasintheten
treatmentarmsofthepainandsufferingscenario,thereare33observationsoutof2463
(1.3%)above$100million,or,onaverage,approximatelythreeobservations(33/10=3)
above$100millionper249observations.Thisrepresentsasignificantreductioninoutliers
( χ 21 = 9.11, p=0.002**).Furthermore,inthefiveunbiasedtreatmentarmsinthepainand
sufferingscenario,therearenineteenobservationsoutof1229(1.6%)above$100million,
or,onaverage,approximatelyfour(19/5=3.8)above$100millionper249observations.
Thisalsorepresentsasignificantreductioninoutliers( χ 21 = 5.6, p=0.018*).
Ouranalysisregardingtheeffectofprior-awardinformationonoutliersis
summarizedinTableIbelow.
222
TableI.AbsoluteDifferencesinProportionsofOutliers PunitiveDamages(Raw) PainandSuffering(Raw)
Treatmentrate
Controlrate
Unadjustedp-value
Treatmentrate
Controlrate
Unadjustedp-value
Treatmentvs.
Control
0.9% 5.2% 0.000*** 1.3% 4.1% 0.002**
Unbiasedvs.
Control
1.1% 5.2% 0.000*** 1.6% 4.1% 0.018*
5. Conclusion
The“starkunpredictability”ofawardsforpainandsufferingandpunitivedamages
isarguablyunacceptable.114Wedesire“predictabilityandproportionality,”115but,atthe
sametime,requirejuriestodeterminetheseawardsthroughnothingmorethana
“standardless,unguidedexerciseofdiscretion.”116Awardsforpainandsufferingand
punitivedamagesshouldbeboundtogether,inthesensethatlikecasesresultinlike
outcomes.Butcourtshavebeenunwillingtobindsuchoutcomestogetheractivelybyusing
awardsincomparablecasesasguidanceforawarddeterminations.
TheLogicofCCGaddressedmajorobjectionstotheuseofprior-awardinformation
toguideawarddeterminations,andarguedthatCCGnotonlyreducesthevariabilityof
awards,butimprovesaccuracy—thatis,biasandvariance—generally.Inparticular,the
paperreliedoncertainbehavioralassumptionstoexplainwhyanyintroductionofbias
causedbyCCGwouldbewelloutweighedbyareductioninvariability;andthatsucheffects
114ExonnShippingCo.v.Baker,554U.S.471,499(2008).
115Paynev.Jones,711F.3d85,94(2dCir.2013).
116Jutzi-Johnsonv.UnitedStates,263F.3d753,759(7thCir.2001).
223
wouldbesufficientlypredictablethat,absentextraordinarycircumstances,courts
generallyneednotbeconcernedregardingwhetherornotCCGwillimproveaccuracyina
particularcase.117Itconcludedthat,“[i]nshort,wecanexpectthatareasonablemethodfor
identifyingprior‘comparable’caseswillresultinprior-awardinformationthatislikelyto
improve[accuracy,andthus,]reliability.”118Furthermore,asecondpaperderivedvarious
mathematicalresultsdemonstratingtherobustnessofCCGmethodstoawiderangeof
conditions,includingthoseinvolvingtheidentificationof“misaligned”priorcases.119But
theseresultsrelyonthesamebehavioralassumptionsasthoserelieduponinTheLogicof
CCG.
Thepurposeofthecurrentstudyistoexaminewhetherthebehavioralassumptions
relieduponinthesepapersarejustified—thatis,whethertheyaresupportedbythedata.
Inparticular,weareinterestedintesting,behaviorally,whetherprior-awardinformation
improvesaccuracyunderarobustsetofconditions,andwhetherjurorsbehaveasthe
modelpredictsinresponsetobiasandvariabilityconditions,andprior-awardinformation
generally.
Inthepresentstudy,wefindthatprior-awardinformationimprovesaccuracy,not
onlywhensuchinformationisunbiased,butalsowhenitisbiased,andevenbiasedandlow
variability.Thatis,evenwhenthepriorawardsarenarrowlydistributedarounda
“misaligned”center—onethatissubstantiallylessthanthe“correct”center—thebeneficial
117SeeTheLogicofCCG§4.
118Id.at21.
119SeeBavli&Chen,supranote50.
224
effectsofprior-awardinformationwithrespecttorandomvariation,orjudgment
variability,aregreaterthanthedetrimentaleffectswithrespecttotheexpectedsizeofthe
award.Thus,anyerrorcausedbythedistortionofawardsize,ortheintroductionofbias,is
outweighedbythereductioninerrorcausedbyreducingdispersion.
Indeed,thisisconfirmed,andgivenadditionalcolor,byourotherfindings.First,itis
clearfromourdescriptivestatisticsthatawardsinthepunitivedamagesscenarioandthe
painandsufferingscenarioareextremelyunpredictable.Second,wefindthat,inadditionto
itseffectonrandomvariationgenerally,prior-awardinformationhasasignificant
downwardeffectonspread.Wealsofindthatithasasignificantdownwardeffecton
outliersinparticular.Thus,prior-awardinformationseemstohavebeneficialeffectson
judgmentvariabilityatagenerallevel—itreducesspread,thefrequencyofoutliers,and
variancegenerally.Note,however,thatanumberoffindingsregardingspreadindicatethat,
ifthepriorawardsaresufficientlyvariable,theymaycausesomesubsetofawardsto
increaseinvariation,evenwhiletherandomvariationofawardsmaydecreaseoverall.
Third,althoughwedonotarriveataconclusivefindingregardingtheeffectofunbiased
prior-awardinformationonmagnitude—e.g.,weareunabletoconfirmtheresultofSakset
al.thatunbiasedprior-awardinformationcausesnochangeintheamountsawardedand
thereforenointroductionoferrorintheformofbias120—thedataprovideevidencethat
biasedprior-awardinformationhasasignificantdownwardeffectonmagnitude,as
predicted.Fourth,inlinewiththebehavioralassumptionsinTheLogicofCCG,wefindthat
120Saksetal,supranote20at249-53.
225
lowvariabilityprior-awardinformationhassignificantlygreaterinfluenceonaward
determinationsthanhighvariabilityprior-awardinformation,andthereforesignificantly
greaterimpactonspreadandmagnitude.
Note,however,thattheeffectofprior-awardvariabilityonspreadandmagnitude
mayinteractwiththeeffectdescribedabove,wherebyhighvariabilitypriorawardsmay
increasethespreadofcertainawarddeterminations.Specifically,itispossiblethat,for
highlyvariablepriorawards,twoeffectsmayinteract:1)thehighlyvariablepriorawards
haveareducedinfluenceonawarddeterminations(relativetolessvariablepriorawards),
resultinginamutedeffectonspreadandmagnitude;and2)thepriorawardsmayhavean
upwardimpactonspreadandmagnitude.Itisunclearwhicheffectwoulddominateina
particularapplicationofCCG;butourfindingssuggestthatthelattereffectwould,atmost,
beconcerningwhenthepriorawardsareextremelyvariable—andeventhen,asevidenced
bythedata,thepriorawardsarelikelytoimproveaccuracyonbalance.
Althoughweuncoversubstantialevidenceinsupportofourhypothesesandthe
argumentinTheLogicofCCG,thereareanumberofimportantlimitationstoourstudy.
First,ashighlightedabove,someresultsgiverisetothepossibilityofeffectsthatarenot
describedbyourhypotheses,orthatweexplainaseffectsrelatedtomeasurement.
Althoughtheseissuesaregenerallyunsurprising,andourexplanationsperhaps
uncontroversial,conclusivereasoningmayrequireadditionalexamination.
Second,theexperimentalunitsinthisstudyaremockjurorsratherthanmockjuries,
whereasjuriesaretheunitsatissueinthecontextofreal-worldawarddeterminations.Of
course,juriesarecomposedofjurors,andthebehaviorofjurorsarelikelycloselytiedto
226
thatofjuries;nevertheless,extendingconclusionsfromthepresentstudytojuriesrequires
additionalinferencethatshouldbeconsideredcarefully.Forexample,itislikelythatthe
randomvariationofawardsislessforjuriesthanjurors,wheretheformerdeliberateand
combine—insomesense,compromiseover—heterogeneousviewsregardingan
appropriateaward.121
Third,ourexperimentalunitsaremockjurors,ratherthanreal-worldjurorswho
decideanawardfollowinganactualtrial(ratherthanadescription).Inasense,thisstudy
isasimplified“laboratory”experimentaimedatstudyingjurorbehavior.Amoreideal
(althoughfarcostlier)experimentwouldinvolveaninterventioninreal-worldaward
determinationsusingjuriesratherthanjurors,andreal-worldjuriesinthecontextofreal-
worldtrials.Forexample,thevariabilityofawardsmaybeexaggerated,becausemock
jurorstreatthesituationashypotheticalandignorecertainrealconsequencesofextreme
awards,suchasbankruptcies,jobloss,etc.122Notethatextremeawardsareobservedinthe
realworld,butlikelylessfrequently(andperhapslessdramatically)thaninsurvey
experiments.Additionally,thesummarydescriptionprovidedtoparticipantsineachlevel
ofscenarioislikelytoaffectthevariabilityofawards(bothincontrolandactivetreatment
conditions)relativetoreal-worldtrialsinwhichmultifacetedevidentiarysupportis
providedtosubstantiateargumentsbytheplaintiffandthedefendant,andpresidedover
byajudge.
121SeeDiamondetal.,supranote7,at316(comparingjurorandjurydamageawards);Sanders,supranote13,at494-96(discussingcriticismsbasedonthedisparitybetweenjuror-basedstudiesandjuryawards).
122Ontheotherhand,itispossiblethatsummarydescriptionsarelessemotion-provokingthanreal-worldtrials,andthereforeweighintheoppositedirection.
227
Fourth,weusedMechanicalTurktoadministerthestudy.Althoughwecompared
thepopulationofMechanicalTurkuserstothepopulationofindividualsonU.S.juries,and
concludedthatthesepopulationsaresimilarbasedonthecovariatesexamined,thereare
likelytobesomedifferencesthatmayaffectourresults.123Additionally,althoughwe
attemptedtoexcludeindividualsnotqualifiedforparticipationonaU.S.jury,neitherour
technicalinclusioncriterianorourstatedinclusioncriteriaensuredcompliance,andwedid
notexpecttoexclude100%ofindividualsineligibleforjuryservice.Totheextentthat
certainparticipantsshouldhavebeenexcludedfromthestudybasedontheirineligibility
toserveonaU.S.jury,andtotheextentthattheirresponsestooursurveydifferfromthe
responseswewouldreceivefromthetruepopulationofeligiblejurors,suchparticipation
mayaffectourresults.
Notwithstandingtheselimitations,andothers,ourfindingsprovidestrongevidence
thatCCGimprovesaccuracyunderarobustsetofconditions,andthatthebehavioral
assumptionsandconclusionsinTheLogicofCCGaresupportedbythedata.Insummary,
ourresearchprovidessubstantialsupportfortheargumentthatCCGisaneffectivemethod
forreducingtheunpredictabilityofawardsforpainandsufferingandpunitivedamages,
whilepreservingthediscretionofthetrieroffactandimprovingtheaccuracyofawards
generally.
123SeegenerallyConnorHuff&DustinTingley,“WhoAreThesePeople?”EvaluatingtheDemographicCharacteristicsandPoliticalPreferencesofMTurkSurveyRespondents,2015Research&Politics1(2015).