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The Structure of Error Componentsin 2010 Census Coverage Error Estimation: P-sample estimates

Mary H. Mulry & Bruce D. SpencerU.S. Census Bureau Northwestern Univ.

2010 International Total Survey Error Workshop June 15, 2010

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Census Coverage Error• Net error = omissions – erroneous enumerations

= True Pop – census• DSE used to estimate True Pop

• Enumeration sample (E-sample)• Population sample (P-sample)

• Components of census coverage:Erroneous enumerationsOmissions = net error + erroneous enumerations

(weighted P-sample not suitable for component error)

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Error structure for component errors

• Recent studies (Mulry 2008 2009, Spencer 2008 2009)

• Have general design for simulation to study synthesis of sampling and nonsampling errors

• Have decompositions of E-sample & P-sample nonsampling errors as functions of field & processing errors for net error & component errors• Have considered the data available from evaluations• E-sample models presented at 2009 ITSEW

Dual System Estimator

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DSE = Enumerations not imputed

Correct enumeration rate __________________________________________

Match rate

from P-sample

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Focus on P-sample• Match rate estimates census enumeration

rate for DSE• Sample selected independent of census

• 170,000 HUs in US; 7,500 HUs in Puerto Rico• Interviews conducted Aug – Oct 2010

• Census Day was April 1, 2010• Followup conducted early 2011 after initial

matching to collect more info on unresolveds• Final matching after Followup

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P-sample seeks to answer to 2 questions

• Is person in the P-sample?• Has to live in HU on Census Day• Complication for usual residence: Some

move between Census Day & Interview Day

• Does the person have a matching census enumeration at usual residence on Census Day?

Interview asks(paraphrased)

• Who lives here now?• Did each person live here on Census Day?• If not, where did the person live?

• includes probes to aid memory

• Did anyone else live here on Census Day?• If yes, where did they move?

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People in P-sample

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In-mover moves into sample block after Census Day

P-sample out-mover moves to Group Quarters or out of US after Census Day

Stable Resident lives in sample block on Census Day & Interview Day

Sample block

P-sample status

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HU in HU out not HU HU in HU out not HUStable resident X XIn-mover X XP out-mover X XNP out-mover X XInterloper X XOut-of-scope X

Census Day Interview Day

Yellow = in the P-sample

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Types of errors in data affecting P-sample status

• Membership in housing unit population• Usual residence on Interview Day• Usual residences on both Census Day

& Interview Day• Geocoding housing unit interviewed

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How errors in P-sample status occur

Failure to detect

False detection

Types of errors• Population member• IntD usual residence• CenD & IntD usual res.• Geocoding

Truth: Stable Resident in P-sample

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Int Day in HU out of sample NP out-mover

Error Coded out of sample

InterloperInt Day & Cen Day in HUs out of sample

Not in HU Pop (GQ or out of US on Cen Day)

Out-of-scope

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Errors in data causing errors in match status

• Usual residence on Census Day• Causes search for match to look in wrong

place• Identification of census enumeration• Geocoding housing unit

Truth: Stable Resident has match

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Cen Day in HU out of sample

In-mover nonmatch

Error Coded

Stable residentnonmatch

HU geocoded in wrong block

Enumeration not found since items missing

Stable resident nonmatch

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Missing items can lead to problems in finding a match

Census

Joe Anders 40

Sue Anders 38

B. Anders 16

P-sample

Joe Anders 40

Sue Anders 38

Bob Smith 17

Jim Smith 15?

“B.” may be Bob, or Jim, or a 3rd son

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P-sample x

(geocoding error)

search area

Census x

(true)

Geocoding error causes listing HU in the wrong block. Census enumerates in correct block. Match to census enumeration outside the search area is not found. P-sample person is coded nonmatch

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Sources of errors

• Processing errors• 2 studies evaluate 2010 CCM

• Data collection errors• 4 studies evaluate for 2010 CCM

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Info on processing error

• Matching Error Study• All types of errors

• Administrative Records Study• Types of error: ID enumeration, HU pop

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Info on data collection error

• Respondent debriefings• Types of error: HU pop, CenDay & IntDay usual residence

• Study of Missed Housing Units• Type of error: geocoding

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Info on data collection error

• Recall bias study• Type of error: CenDay usual residence

• Comparison of census operations with CCM results• Type of error: geocoding

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Next steps

• Design estimators of E-sample & P-sample nonsampling errors • For use in simulation study to

synthesize errors • Avoid double counting errors

• Continue to develop better understanding of error structure

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mary.h.mulry@census.gov U.S. Census Bureau