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Electoral Studies 29 (2010) 648–660

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Electoral Studies

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Electoral reform and the mirror image of inter-party and intra-partycompetition: The adoption of party lists in Colombia

Mónica Pachón b, Matthew S. Shugart a,*aDepartment of Political Science, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0510, USAbDepartment of Political Science, Universidad de los Andes, Carrera 1 No 18A 10, Bogotá, Colombia

a r t i c l e i n f o

Article history:Received 16 September 2009Received in revised form 6 April 2010Accepted 29 June 2010

Keywords:Electoral reformColombiaSNTVProportional representationPreference voteParty listsOpen listsClosed listsLogical model

* Corresponding author. Tel.: þ1 858 534 5016; faE-mail address: mshugart@ucsd.edu (M.S. Shuga

i For example, the “mixed-member” systems ofand Venezuela.

0261-3794/$ – see front matter � 2010 Elsevier Ltddoi:10.1016/j.electstud.2010.06.005

a b s t r a c t

The Colombian case offers a rare opportunity to observe effects of electoral reform wheredistricting remains constant. Only the formula changed, from extremely ‘personalized’(seats allocated solely on candidate votes) to ‘listized’: seats are allocated to party lists,which may be either open or closed. Electoral reform has effects on both the inter-partydimension (the number of parties competing) and the intra-party dimension (the extent ofcompetition within parties). Consistent with theoretical expectations, the inter-partydimension features an increased number of parties in the low-magnitude districts anda decrease in the high-magnitude districts. On the intra-party dimension, the impact“mirrors” the inter-party: less competition in smaller districts, yet more in larger districts.

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1. Introduction

In recent decades, numerous democracies havereformed their electoral systems. Typically, reforms entailrevamping districting arrangements, often adding a secondtier of seat allocation.i Far rarer are reforms that funda-mentally change the seat allocation formula, but maintainthe same districts as the pre-reform system. Using one ofthese rare cases, Colombia 2002–2006, we undertake ananalysis of the effect of reform.

Colombia’s reform altered the “incentive to cultivatea personal vote” (Carey and Shugart, 1995) by replacinga system that was essentially the single non-transferablevote (SNTV) with party-list proportional representation(PR). District boundaries were unchanged, as were their

x: þ1 858 534 7130.rt).Japan, New Zealand,

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magnitudes (number of seats, denoted M). The criticalchange is that now a party wins seats based on thecollective votes earned by its list.

Prior to the reform, collective party-vote shares wereirrelevant to the allocation: the system awarded seats to thetop-M vote-winning candidates, regardless of party.Because of this feature, we refer to the pre-reform systemas personalized. The post-reform system allocates seats toparty lists before taking individual candidates into account,so we describe the reform as listization. In theorizing aboutthe impact of listization, and exploring effects empirically,we are interested in the outcomes for both the number ofpartiesdthe “inter-party dimension”dand within-partycompetitiondthe “intra-party dimension.” We argue thatthese two dimensions are systematically related, becausemoving from a personalized to a listized electoral systemprovides a fundamentally different calculus for individualpoliticians and parties. Put simply, when collective votetotals matter, the incentive to cultivate a party vote domi-nates over the incentive to cultivate a personal vote. This is

ii As we explain in Section 6, the lowest intra-party competition meansan absence of at least one losing candidate who was close to beating theparty’s last winner (in OLPR or SNTV), or else a closed list.iii There are also special national districts (for Afro-Colombians in the

Senate and for indigenous in the House), excluded from our analysis.

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660 649

a complete reversal from the priorities given by the pre-reform system, where personal vote incentives dominated.Further, we argue that this dominance of party-basedincentives holds evenwhere lists are “open” (i.e. voters castvotes for a specific candidate on a list). Our analysis of boththe inter-party and intra-party effects of electoral reform inColombia is driven by this fundamental reorientation ofinstitutional incentives. We now offer an overview of ourmain findings, on each dimension of competition.

Regarding the inter-party dimension, our main findingis that listization results in a decrease in the number ofcompeting parties in larger districts, but an increase in low-magnitude districts. The impact at larger-magnitudedistricts is a straightforward product of the incentive ofcandidates from minor parties to aggregate onto largerparty lists due to the new system’s awarding of seats basedon collective partisan performance. At lower magnitudes,on the other hand, the personalization of the former systemhad implied that candidates could compete under the sameparty label without their votes helping elect a rival. Withlistization, this tactic is no longer feasible, precisely due tothe aggregating of votes to party lists. Thus listization inhigh-magnitude districts results in mergers of smallerparties into fewer but larger parties; in low-magnitudedistricts it results in splits of formerly dominant parties.Both of these results are driven by the fundamental changein the incentive to cultivate a personal vote: in the oldsystem, a candidate’s personal vote was the only criterioninwinning a seat, but in the new system the first criterion iscollective party votes.

Another aspect of Colombia’s reform allows us yet moreleverage over the question of the impact of listization.Uniquely, as far as we know, Colombia’s new PR systempermits parties the option of presenting either a “closed” oran “open” party list. When a list is closed, individualcandidates’ order of election depends on their party-provided ranks. When the list is open, ranks depend on thenumber of “preference votes” cast for specific candidates.This party option allows us to challenge conventionalwisdom regarding the impact of electoral systems on theincentive to cultivate a personal or party reputation (Careyand Shugart, 1995; Ames, 1995; Chang and Golden, 2007).Open-list proportional representation is typically seen ashighly personalized, akin to SNTV, in contrast to the mosthighly “party-centered” of all systems, closed list propor-tional representation. In contrast, we find that the morefundamental distinction is between personalized and lis-tized systems.

We will show–surprisingly if we go by conventionalwisdom–that it was the most personalized elements ofColombia’s party system that opted for closed lists: (1) localpoliticians seeking to differentiate themselves froma formerly dominant party in small-magnitude districts,and (2) national political figures seeking to use their ownpersonal reputations to carry their new parties into office.By contrast, most candidates in 2006 ran on open lists,particularly in the largest-magnitude districts. It isprecisely when district magnitude is high that scholars ofpersonal vote incentives (Carey and Shugart, 1995) suggestthat intra-list competition among large numbers of candi-dates undermines party-based incentives. Yet the evidence

we present below suggests that, far from being an obstacleto party-building, open lists may have been essential to it,by giving disparate political forces the incentive to aggre-gate onto lists competing against other lists.

Moreover, we present evidence that shows that insmall districts, intra-party competition was reduced by thereform compared to the personalized pre-reform system.ii

Yet the reform led to substantially greater intra-partycompetition in large districts than was observed pre-reform. This again challenges Carey and Shugart’s (1995)claim that greater incentive to cultivate a personal voteis driven by intra-party competition. Instead, we suggestthat it may be necessary to de-couple these concepts, andthat a more personalized system of seat allocation (e.g.SNTV) does not necessarily imply greater intra-partycompetition.

Taken together, these findings tell us that the inter-party and intra-party dimensions “mirror” each other. Inthe transition from personalized to listized allocation,where competition increases on one dimension, it tendsto decrease on the other. At higher magnitudes, inter-party competition is reduced (fewer competing parties),but it is precisely in these districts where intra-partycompetition is increased after reform. The oppositepattern prevails in smaller districts. Now, before turningto a fuller development of the logic by which the reformproduces these effects, and our empirical analysis, weoffer a brief introduction to the country case and itselectoral systems.

2. Colombia’s electoral systems

Despite the country’s high level of violence, Colombiahas been a functioning electoral democracy for over fiftyyears (Welna and Gallon, 2007). At one time, the country’spolitics was dominated by two traditional parties, Liberaland Conservative, which shared legislative and alternatedexecutive power under the National Front (1958–1974; seeHartlyn, 1988). After the end of the Front, and especiallyunder a new constitution after 1991, the traditional parties’dominance rapidly broke down (Taylor, 2008).

Colombia’s congress consists of a House of Representa-tives, elected in 33 districts with magnitude (M) rangingfrom 2 to 18 (mean 4.8, median 4), and a Senate elected ina single national district, with M ¼ 100.iii The wide cross-district and cross-chamber variation in district magnitude,but with no magnitude change across elections, offerssubstantial theoretical leverage on the impact of listizationon electoral coordination.

The seat allocation formula, in use for decades prior to2006, was simple quota and largest remainders (SQLR).This formula is a standard PR formula (Lijphart, 1994;Taagepera, 2007) when applied to party lists. However, inColombia, it was applied to personal lists. Typically a party,

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660650

especially a large one, would have numerous candidatescompeting on separate personal lists bearing its party label.It was this personalization of the lists that rendered itequivalent to the single non-transferable vote, or SNTV(Cox and Shugart, 1995; Taylor, 2008: 85, 110 ff).

Under SQLR, a simple (Hare) quota (votes divided bymagnitude) was sufficient to ensure a seat. Seats unfilledafter allocation by quotas were filled by remaindersdforeach list, the original votes, minus quotas useddone per listin descending order, until all seats were filled. In Colombiait had become rare by 2002 for any of the myriad personallists to win more than one seat. The result was that eachlist, regardless of party label, served as the vehicle for thecampaign of just one candidate. When no list wins suffi-cient votes for more than one seat, allocation via SQLR isexactly the same as if it were SNTV: each of theM largest listswins a seat. This was the case for all House seats in 2002,iv

and thus we can treat that election as SNTV.v The picture inthe Senate was only slightly different: in each election from1994 to 2002, 100 seats were filled by 97 lists.

We will use the case of the district of Bogotá (M ¼ 18) toillustrate how the pre-reform system promoted personali-zation. In 2002 there were 286 lists registered, half ofwhich bore the Liberal label. Thirty lists, including eightLiberal, won at least 1% of the vote. Each of the eighteenlegislators was elected on his or her own list; i.e. thewinners were the candidates at the top of the lists that hadthe eighteen highest vote totals. Of these eighteenwinners,four were Liberals. The remaining fourteen seats were wonby fourteen different parties. Of these one-seat parties, onlytwo also had a losing list place as high as thirtieth in thedistrictvi; six of them presented exactly one list, not takingany chances on diluting their votes across separatecompetitors.

Thus this example from Bogotá clearly shows bothdimensions of competition. Some competitive candidates,particularly Liberals, were engaging in intra-party compe-tition, likely seeking to maximize their odds of victory bydifferentiating themselves from candidates bearing thesame party label. Others could be said to be engagingprimarily in inter-party competition, because theywere theunique (or only remotely competitive) candidate of theirparty; their best chances of victory perforce would be indefeating candidates bearing other party labels. In any case,each of these winners won on his or her own personalreputation: the top 18 candidates won–this is the de-factoSNTV feature–and it would not have mattered to the allo-cation process if these winners had represented 18 distinctpolitical parties or 18 separate candidates competingwithin one party.

Marking a major departure with previous practice, thepost-reform formula is a strictly party-list system. Eachparty is limited to a single list per district, and seats are

iv It had also been the case for all seats in 1998.v These lists typically contained other candidates, and thus, unlike the

one-candidate “lists” of a “normal” SNTV system, they potentially couldearn more than one seat (Candidates other than the list-head could serveif an elected member resigned midterm.).vi The liberals had 4 more in the top 30, in addition to their 4 winners.

allocated by D’Hondt divisors,vii favoring larger lists(Taagepera, 2007: 85–9) relative to SQLR. In the district ofBogotá in 2006, there were eight parties that won seats(down from fifteen in 2002), including three that won foureach and two parties with two seats. The smallest vote totalthat earned a party a seat was 3.7%, a dramatic differencefrom 2002 when nine of the parties that won a seat did soon less than 3.5% and one had only 1.5%. Clearly, the newsystem created incentives to aggregate on to larger partylists in this large district. Nowwe consider some theoreticalimplications of listization.

3. Listization and the mirror of the inter-party andintra-party dimensions

With the electoral reform, Colombia has had each of thethree major multiseat district formulas: single non-trans-ferable vote (SNTV), closed-list proportional representation(CLPR), and open-list proportional representation (OLPR).In fact, these three systems are logically connected in a waythat is not typically recognized. The connection is throughhow they affect whether candidates tend to enter the raceon a large party, where they will one of several viablecandidates, or on their own party in which they will be thesole or dominant candidate. We develop this argument inthis section, first comparing the formulas, and thenconsidering the impact of district magnitude.

3.1. How the allocation formulas affect vote-seeking

Listization changes the balance between personal andparty reputation-seeking in the competition for seats.Under SNTV, personal vote strategies dominate, because itis a top-M system. Under party-list PR, on the other hand,personal votes affect candidates’ prospects only in thecontext of collective vote shares won by their parties.

The SNTV rules allowed any aspirant for office to choosewhether to run under the banner of an existing party orregister a new one. Many parties (especially Liberal) fol-lowed “permissive” rules of endorsement, as seen in ourexample above from Bogotá, rarely denying candidates theright to use of their label. Likewise, the rules for forminga new party or electoral “movement” were permissive(Pizarro, 2001; Pachón, 2001). Thus it was relatively easyfor a candidate to run either against other candidates ina larger party or to launch an entirely new party.

Because the allocation rule did not take parties intoaccount, choosing a party label was not about sharing, orpooling, votes with co-partisans. Instead we can assumethat candidates selected the party label that they expectedwould maximize their own personal vote. The value ofparty affiliation had to come from something other than theelectoral formula. For candidates in a large party and somewell-established smaller parties the value of party affilia-tion would be the identification with a pool of voters who

vii A list’s votes are divided by a series of whole numbers (1, 2, 3,.) andseats are assigned to the resulting quotients until all are filled. The reformalso introduced low legal thresholds: half a Hare quota in the House(which is much too small to have impact) and 2% in the Senate.

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themselves identify with the party. For others, party labelwas simply a way of branding a de-facto independentcandidacy.

Choosing the label of an established party with otherviable candidates in the district is an intra-party strategy.This term signifies that the candidate competes with othersbearing the same label. In order to maximize its collectiveseat total, the party would need a means to coordinateamong its multiple aspirants to ensure that some numberof candidates (greater than or equal to one) would finish inthe top M. The need to coordinate in order for a party toensure a collectively optimal distribution of its votes isa classic problem in SNTV.viii Other candidates enter thecontest under a label with no other viable candidate in thedistrict; we call this an inter-party strategy. The reason forthis term is straightforward: such an entry decisionincreases by one the number of distinct party labelscompeting in the race for the district’s M seats, rather thanincreasing the number of candidates in a party with otherviable candidates. The important point about the pre-reform SNTV system is that either strategy can be under-stood as a means for cultivating the candidate’s personalvote, because the only calculation that matters is how tomaximize one’s chance of finishing with a top-M total.

The calculation changes under party-list PR: in whichparty does the candidate have the greatest chance of elec-tion? If s is the number of seats a list wins, the answerdepends on having a top-s preference–vote rank within anopen list or a top-s party–given rank on a closed list. Unlikeunder SNTV, this calculation involves an estimate ofcollective impact: what matters first is what s will be, andonly then (if at all) comes the question of the votes won bythe candidate personally.

3.2. The effect of district magnitude on strategy, contingent onallocation formula

District magnitude enters into the calculations justsketched because of the effects it has on the number ofvotes required to win a seat on personal votes alone, ina personalized system, or on the number of votes a listneeds to win a certain number of seats, in a listized system.The literature on SNTV has separately addressed itstendencies to promote both intra-party and inter-partystrategies. As already noted, there has beenmuch emphasison candidates’ competing for seats with co-partisans,giving rise to collective problems of coordination for partyorganizations. The literature has also noted the prevalenceof inter-party strategies, which can lead to SNTV’s being“super-proportional” (Taagepera and Shugart,1989: 170 n5,Cox, 1996 ix) because needing to coordinate across multiplecandidates makes it difficult for larger parties to translatetheir votes into a given number of winnable seats. Thesmall parties, by contrast, simply run one candidate (or takesteps to ensure the bulk of their votes are concentrated onone). In the Bogotá example above, the last six winners had

viii For an overview, see Grofman et al., 1999.ix For a different view, based on aspects of the Japanese case that are not

relevant for our purposes, see Christensen and Johnson (1995).

between 1.47% and 2.00% of the district vote and four ofthese were the sole or dominant candidates of their party.Meanwhile, Liberals only narrowly failed to elect twoadditional candidates whose vote percentage was greaterthan 1.25%. In other words, with a better coordination ofvotes, the Liberals, three of whose four winners had over1.75% of the vote, might have elected at least six rather thanjust four. Because its coordination was sub-optimal, theLiberal Party displaced some seats to parties whose tinyvote shares were concentrated on one candidate. This iswhat is meant by the “superproportionality” of SNTV, and itimplies a very steep slope when the number of competingparties is graphed against district magnitude–as we showbelow.

In small-magnitude districts (2–4 seats), on the otherhand, we expect intra-party strategies to dominate underSNTV. When district magnitude is small, only one or a fewlarger parties tend to be competitive. Thus aspirants aremore likely to seek to tap into a pool of voters in the districtthat identify with one of these existing locally dominantparties (i.e. one that will have at least one other viablecandidate).

The logic we just sketched suggests that intra-partystrategies dominate at lowmagnitude (few parties canwin,with multiple candidates seeking to be the representativesof these parties), but that at high magnitudes, inter-partystrategies dominate (many small parties may win seats, butmost will have little intra-party competition because theyare effectively one-candidate parties).

What about the balance of strategies when the alloca-tion has been listized, as in Colombia, 2006? We expecta mirror image of strategic adaptation. That is, inter-partystrategies tend to replace intra-party strategies, and viceversa. Consider the logic for small magnitudes first, wherewe already stipulated that intra-party strategies dominateunder SNTV. To understand the changed strategic incen-tives, we must consider the impact of the intra-partydimension on the inter-party. Because SNTV entails purelypersonalistic allocation, intra-party factions may coexistunderneath the banner of the same party. Candidatesrepresenting different intra-party factions can have theircake and eat it, too: Align with a major party, perhapssignaling an ability to deliver clientelistic benefits from thecentral government, while simultaneously cultivatingindependent personal reputations. If a large party has atleast two such politicians under its banner in a two-seatdistrict, for example, it may win both seats, provided theyhave roughly equal personal appeal.

However, coexistence is made more difficult after listi-zation, because even if the list is open to intra-partycompetition, now a vote for any candidate pools to the listas a whole. Thus a vote for one candidate may help electa rival candidate instead. This vote-pooling feature of listsgenerates incentives for rivals to differentiate themselvesby using different labels, enhancing the value of inter-partystrategies. Thus in small districts, previously dominantparties practicing intra-party vote-division can be expectedto yield party splits, increasing the number of competingparties.

At larger magnitudes, we expect the mirror of thisadaptation. On the inter-party dimension, the number of

x He previously had been a Liberal, but did not seek that party’sendorsement. Instead, his supporters formed an electoral “movement,”Primero Colombia (Colombia First).xi We count as a separate “party” any list bearing a distinctive label,

even if part of one of the traditional “families.” Other experts agree, e.g.,Taylor (2008) and Crisp and Ingall (2001).

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660652

parties in the largest districts is straightforward: party listallocation formulas (especially D’Hondt divisors) are less“permissive” than SNTV to the representation of smallparties. Thus, following listization, the smallest partieshave an incentive to merge their efforts into larger lists.Incumbents who may have been elected on distinct partylabels, plus newcomers who might have tried the samestrategy under SNTV, instead merge their efforts intoa larger party more likely to pass the higher threshold fora list to gain even one seat.

Examples from both a small and a large districtdemonstrate these strategic changes. The two-seat districtof Chocó in 2002 was dominated by the Liberal party, threeof whose candidates were closely competitive. In 2006,one of the incumbents won reelection under the banner ofCambio Radical on a closed list (which was not close towinning the second seat). The other seat was won bya candidate of the new party known as La U (describedbelow), who dominated his open list with about ten timesthe preference votes of his listmate. The Liberals, present-ing a closed list, finished a close third. Thus the districtmoved from 3-candidate competition (all of one party) to3-party competition (but with no effective intra-partycompetition).

Now consider Valle,M¼ 13. In 2002, the United PopularMovement (MPU) and the Humbertistas each presentedtwo candidates who earned similar vote totals; however,only one (from MPU) was elected. In 2006, these twoparties combined on one list, under the MPU label, andwith a very similar vote share to their aggregate votes of2002, won two seats. The MPU incumbent, seekingreelection, contributed his personal vote to the list, thoughhe was defeated, as was one of the repeat Humbertistacandidates. Whereas in Chocó the main dimension ofcompetition changed from intra-party to inter-party, inValle it was the reverse.

3.3. Summarizing the expectations: the mirror image ofcompetition

Our theoretical expectation is that the two dimensionsof competition are a “mirror” of one another followinglistization of formerly personalized seat allocation: inlarger-magnitude districts, where parties merge andthereby reduce inter-party competition, they tend tobecome more competitive internally; however, in smallerdistricts where parties split and thus generate more inter-party competition, they tend to become less competitiveinternally. Overall, changes on the intra-party dimensionare potentially important for longer-range goals of theadvocates of Colombia’s reform, as increased intra-partycompetition in large districts may dampen the much-crit-icized clientelism of Colombia’s fragmented party system(Pizarro, 2001; Santana, 1998). Nonetheless, one of ourfindings is a challenge to scholarly wisdom about intra-party competition. Contrary to expectations that closedlists generate more powerful incentives to cultivatecollective party reputations than do open lists (Carey andShugart, 1995), we will provide evidence that it is themost “personalized” parties in Colombia’s first party-listelection that presented the closed lists.

In our empirical analysis, we explore changes, at thedistrict level, in two primary outcome variables: thenumber of parties that earn votes, and the competitivenessof the intra-party dimension. Before turning to the district-level analysis, we offer a brief overview of the two elec-tions, in order to situate the district-level contests fromwhich our data comewithin their broader national politicalcontext.

4. Setting the scene: Colombia’s elections of 2002 and2006

The March 2002, congressional election represented thenadir of electoral support for the two traditional parties. InMay 2002, their decline was confirmed when Colombianselected their first independent president, Alvaro Uribe.x

Table 1 shows aggregate results of the 2002 and 2006House and Senate elections. Notably, Liberals retaineda plurality in 2002, but only 31% of the vote; their supportdeclined further in 2006.

Many pro-Uribe candidates in 2002 sought congres-sional seats under new party labels, accelerating anongoing proliferation of small parties (Moreno, 2005). By2006, with Uribe-seeking reelection, the Liberal party split.The “official” Liberals had opposed Uribe in his first termwhile other Liberals joined his legislative coalition andcontested the 2006 election under new banners. It is withinthe context of this new national cleavage over Uribe thatelectoral reform passed in 2003 as an effort by both tradi-tional parties and the leftist opposition to enhance thevalue of party labels in legislative races (Shugart et al.,2007). The new party-list system thus made it untenablefor both supporters and opponents of the president tocoexist under a common label, because now a vote for anycandidate on a given list pools overall its candidatesdinmarked contrast to SNTV.

Table 1 indicates that the most successful party in 2006was the new Partido Social de Unidad Nacional, knownpopularly as Partido de la U (to signal its uribista stance). Itsmembership consists of many former Liberals. In additionto la U, two other parties in Uribe’s coalition also performedwell: the Cambio Radical and the Conservatives. The CambioRadical already existed in 2002, but gained new adherentsamong former Liberals and others prior to the 2006 elec-tion. The Conservative Party, one of Colombia’s oldest,regained some of its former strength in 2006, aided by theparty-list system, which encouraged former splinters fromwithin the conservative “family” (Pachón, 2001) to reuniteunder a common label.xi Another new party in 2006 wasthe Polo Democrático Alternativo, combining several smallleftist opposition parties.

The prevalence of inter-party strategies under SNTV iswell displayed in the table’s “other” category. Each “other”

Table 1The 2002 and 2006 congressional elections in Colombia: national results.

Party Senate 2002 House ofRepresentatives 2002

Senate 2006 House ofRepresentatives 2006

Seats % of votes Seats % of votes Seats % of votes Seats % of votes

Partido de La U – – – – 20 17.5% 29 16.7%Polo Democrático Alternativo – – – – 11 9.7% 8 8.2%Partido Colombia Democratica – – – – 3 2.8% 2 2.5%Colombia Viva – – – – 2 2.5% – –

Partido Liberal Colombiano 28 30.6% 54 31.3% 17 15.5% 36 19.0%Partido Conservador Colombiano 13 10.0% 21 11.0% 18 16.1% 29 15.8%Movimiento Nacional 6 4.8% 1 1.1% – – 2 2.0%Movimiento Alas Equipo Colombia 3 3.3% 4 2.3% 5 4.7% 7 4.3%Movimiento Integracion Popular 4 3.0% – – – – – –

Movimiento Colombia Siempre 2 2.9% 3 1.3% – – – –

Cambio Radical 2 2.5% 7 3.8% 15 13.4% 20 10.7%Convergencia Popular Cívica 1 1.0% 4 2.2% 7 6.2% 8 4.6%Movimiento Apertura Liberal 0 0.0% 5 2.0% – – 5 2.3%Movimiento Integración Regional 0 0.0% 2 0.5% – – 4 1.4%Movimiento de Salvación Nacional 1 0.9% 2 1.4% – – 1 3.0%Others 40 40.9% 58 34.9% 2 2.3% 10 8.4%Total 100 100.0% 161 100.0% 100 100.0% 161 100.0%

Parties in bold were part of the pre-electoral coalition of President Alvaro Uribe Vélez for his reelection in 2006.

Table 2Effective number of parties and presidential candidates, Colombia, 2002–2006.

Effective number of. 2002 2006

10 March 26 May 12 March 28 May

Vote-earning partiesHouse 8.30 8.79Senate 8.93 8.07

Seat-winning partiesHouse 7.39 7.19Senate 9.33 7.18

Presidential candidates 2.56 2.22

Source: Authors’ calculations, according to the Laakso and Taagepera(1979) index.

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660 653

party won fewer than three seats and the total number ofseats for these parties declined from fifty-eight in 2002 toten in the first party-list election. Thus, aided by the elec-toral system, the congress elected in 2006 consisted offewer tiny parties with a primarily local or personalistprofile.

The broader national political context of these twoelections is propitious for our effort to analyze the impactof legislative electoral rules on competition for legislativeseats. Generally speaking, in presidential systems politicalcoordination around the executive contest exerts a “pull”on legislative coordination, complicating the attributionof legislative outcomes to specifics of the legislativeelectoral system (Lijphart, 1994; Shugart, 1995; AmorimNeto and Cox, 1997; Jones, 1999; Clark and Golder,2006; Golder, 2006, Kasuya 2009; Hicken and Stoll,2011). However, in Colombia, and especially in 2002and 2006, these “contaminating” effects of presi-dentialism are almost absent. First of all, the timing ofelections minimizes presidential coattails because legis-lative elections occur before presidential, by elevenweeks. Moreover, Uribe ran as an independent bothtimes, making it difficult for candidates to coordinatearound a smaller number of parties. As a result, therewere multiple parties in both legislative elections iden-tifying as “uribista” rather than a single party seeking tocapitalize on his coattails.

We can also be confident that variation in fragmentationof the upcoming presidential contest did not havesubstantial effects on legislative coordination. The effectivenumber of presidential candidates, a factor found by Jones(1999) to be a significant predictor of the fragmentation ofthe legislative party system, was almost the same in 2006(2.22) as it had been in 2002 (2.56), despite the presence ofan incumbent president in 2006 (a factor found to decreasefragmentation substantially in Jones’s multi-countrysample). Table 2 summarizes the effective number ofparties in each of these contests. As can be seen, the

legislative party system, with effective numbers in the 7–9range, clearly is not affected by the low fragmentation ofthe presidential contest! Quite the contrary: the legislativeand presidential party systems are about as distinct ascould be imagined. Additionally, as Table 2 shows, theoverall effective numbers do not change much from 2002to 2006, suggesting that any effects we find from theelectoral system at the district level are not beingconfounded by shifts in national-level fragmentation.

Now that we have set the political scene by reference tonational dynamics, we turn our attention to the empiricalanalysis of post-reform adaptation at the level of the elec-toral districts. The following empirical analysis is dividedinto two parts, with the first covering the inter-partydimension, while the second covers the intra-partydimension.

5. The impact of listization: the inter-party dimension

On the inter-party dimension, as noted previously, weexpect listization to result in a decrease in the number ofcompeting parties in large-magnitude districts, relative tothe former personalized system. Yet we expect reform toresult in an increase in the number of competing parties in

xii We used an unstructured correlation working matrix to allows us tocontrol for a wide variety of correlation patterns. The coefficients andtheir significance levels are the same for the GEE (shown below) or OLS(not shown).xiii A potential additional variable that could be included in a model ofthe number of parties might be one relating to the impact of the presi-dential election on coordination in legislative districts (Jones, 1999;Hicken and Stoll, 2011). In any case, models (not shown) that includedthe effective number of presidential candidates at the district level in thesubsequent presidential election did not alter our results, nor didentering the percentage of the vote received by Uribe. We also exploredmodels with other control variables available at the district level, such asthe number of violent incidents (which might depress political compe-tition). All of these additional variables were insignificant in most spec-ifications and always left our coefficients of interest substantivelyunchanged.

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smaller districts. That is, we expect inter-party competitionto be characterized principally by mergers of formerlysmall parties in large districts, but splits in formerlydominant parties in small districts.

For analyzing how aspirants for legislative officerespond to incentives of the change from a personalized toa listized system, we are interested primarily in a measureof the number of parties arising prior to votes being cast.Yet we cannot simply count the number of parties on theballot, becausemany of these parties will prove too small tohave a perceptible impact on the race. Thus we needa concept of “pertinent” vote-earning parties, which weshall designate here as pv when it refers to the numberunder post-reform party-list PR, or p0v when it refers to pre-reform SNTV. We will also analyze the “effective” numberof vote-earning parties (Nv, as defined by Laakso andTaagepera, 1979), which weights the parties by theiractual votes cast, for comparability with the nationalfigures reported above (Table 2).

For “pertinent” parties, various cutoffs could be used, forexample one or five percent of votes obtained (e.g.Ordeshook and Shvetsova, 1994; Chhibber and Kollman,1998; Clough, 2007). However, a fixed share of the votethat is useful for national-level data or where magnitude isinvariant is less appropriate for our purposes. We needa measure sensitive to magnitude variation. We willconsider a party as “pertinent” if it won at least 25% of thevote share of the last seat-winning party in any givendistrict. While any cutoff is arbitrary, our definition has theadvantage of not being overly exclusionary (leaving asidesmall parties that might have affected competition) oroverly inclusive (counting truly insignificant parties).

How many pertinent parties “should be” expected? It isuseful to have a baseline, in order to determine whetherlistization indeed has resulted in a change in the partysystem consistent with similar party-list systems. Thereremains in the literature a shortage of district-level analysisof the number of parties (however defined). Accordingly,we rely on Taagepera’s (2007: 244–5) estimate that thenumber of pertinent parties (which he does not defineprecisely) might be approximately:

pv ¼ M:5 þ 2M:25 (1)

Taagepera notes that Equation (1) fits well for manyelections’ worth of data from Finland, which has a similarelectoral system to that adopted in Colombia for 2006.

Using Equation (1) as a starting point, we have two keyobjectives in our exploration of the number of pertinentparties. First, we seek to determine whether and to whatextent the post-reform electoral system, in its first use,corresponded to expected patterns for list-PR systems.Second, we seek to determine the extent to which theresult for 2006 reflects the change that we expect whencompared to the result of the final pre-reform election of2002, under extremely personalized rules: increased inter-party competitiveness at the lowest magnitudes butincreased coordination at the higher magnitudes.

To test empirically the impact of reform, we rana generalized estimating equations (GEE) model (Zorn,2001) in which the level of observation is each district ofthe House of Representatives, before and after reform. Thus

the model includes district magnitude (logged), and thisvariable is interacted with the “treatment” variable,a dummy for electoral reform. The outcome variable is thedistrict-level number of parties (logged), with models runon both pertinent parties (pv) and the effective number ofvote-earning parties (Nv). Our model allows us to see if therelationship between magnitude and number of partieschanges with the reform in-line with our expectations. Weare interested in seeing how the decisions taken by politicalactors in merging or splitting pre-reform parties werereflected in the post-reform election. In doing so, we willalso see how closely the regression estimate corresponds toEquation (1), which was derived by Taagepera as anexpected relationship for systems like Colombia’s post-reform system, independently of our research. The regres-sions are based on House data only, but we also will checkgraphically whether the separate institution of the Senate(M ¼ 100, nationwide) performs as if it were just anotherlarge House district, or whether it follows a different logic.

Our preference for a GEE model over Ordinary LeastSquares (OLS) stems from a concern with potential auto-correlation that could render OLS estimation inappropriate.The autocorrelation of residuals can be expected to occur atthe district level, because elections that take place in thesame district but at different points in time ought to bemore similar than elections occurring in two differentdistricts. GEE allows us to acknowledge and correct for theexistence of the linear dependence amongst the observa-tions.xii The results, displayed in Table 3, strongly supportour expectations–for both outcome variables.xiii Moreover,Fig. 1 shows that there is little difference, in estimating pv,between the line derived from the regression on post-reform data (the dashed black line) and Equation (1)(the solid black line).

Fig.1 also proposes the following expression for the datafrom the pre-reform election:

p0v ¼ :5 M þM:75 (2)

Equation (2) (in solid gray), the derivation of which wewill explain shortly, visibly performs as well in estimatingthe number of pertinent parties in the pre-reform systemas does the purely empirical regression (in dashed gray).The lines for Equations (1) and (2) are extended out toM ¼ 100, the magnitude for the Senate. Based on theplotted results of the 2002 and 2006 Senate outcome, it is

Table 3Regression estimates, number of vote-earning parties before and afterreform GEE population-averaged model.

Dependent variable: Number of pertinentvote-earning parties(logged)

Effective number ofvote-earning parties(logged)

Constant 0.127 (0.084) 0.182 (0.067)Reform (treatment) 0.337 (0.102) 0.319 (0.078)District magnitude,

logged0.952 (0.121) 0.688 (0.105)

Interaction(Reform � Distictmagnitude, logged)

�0.557 (0.133) �0.415 (0.110)

Number ofobservations

66 66

Number of groups 33 33Wald Chi2 74.55 63.82Prob > Chi2 0.000 0.000

Standard errors (in parentheses) adjusted for clustering by district.Link: identity; Family: Gaussian; Correlation: unstructured.Transformed results (taking the anti-logs):Pre� reform p0v ¼ 1:3M:95 N0

v ¼ 1:5:69

Post� reform pv ¼ 2:9M:40 Nv ¼ 3:2M:27

Fig. 1. The number of ‘pertinent’ vote-earning parties, by district magnitude.

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clear that the Senate behaves on this indicator almost as if itwere just another large House district. For pertinent partiesentering the race, this finding confirms the impact of ourvariables of interest, district magnitude and reform, even ina separate institution from the one for which the regressionwas estimated.xiv

Equation (2) is derived from the observation (Table 3)that the intercept for the reform treatment is just overtwice that of the untreated estimate, while the slope isreduced by just over 0.5; this leads to an estimate of theimpact of this sort of electoral reform that may havetheoretical implications, helping us tie the two dimensionsof competition to one another. With trivial loss of precision,the relationship between the pre-reform (p0v) and post-reform (pv) number of pertinent parties is approximately:p0v ¼ pvð:5M:5Þ. If we apply this expression to Equation (1),we get Equation (2). Is there a logical foundation to Equa-tions (1) and (2)? If there is not, it would be just as good toreport the empirical regressions andmove on. However, wecan do better than “post-dictive” regression equations(Taagepera, 2008), because what we want to move on to isthe intra-party dimension. As we have made a consistenttheme of this analysis, these two dimensions are logicallyrelated to one another: listization leads to a decrease incompetition on one dimension at the same time as it leadsto an increase on the other. We see in Fig. 1 a visualdemonstration of the inter-party effect: increased numberof pertinent parties with listization in the smallest districts,but decreased in larger districts. Can the structure ofEquations (1) and (2), with two terms on the right-handside, account for the mirror image of the change in intra-party competition? If so, we may have found a key tolinking the two dimensions.

xiv For Nv, on the other hand, the equation estimated on House datawould predict absurdly high values at M ¼ 100. This is because the largenumber of small parties that meet the standard of pertinence do not winmany votes, and thus have little effect on Nv.

We can think of the number of pertinent parties runningas consisting of two components: (1) the number of partiesthat win a seat in the district, plus (2) some number oflosing parties that reach the threshold of pertinence. This ishow Taagepera (2007) explains the model represented byour Equation (1). For reasons he explains (pp. 118–22) thenumber of seat-winning parties is expected to be, onaverage, M:5, for electoral systems such as list PR. Thus2M:25 (the second term in Equation (1)) would be thenumber of pertinent losing parties expected for any givendistrict magnitude. This term in Equation (1) tells us thatthe there would be, on average, two such parties if M ¼ 1,and that the number rises with magnitude, but at half therate by which the number of winning parties rises.

We can ask ourselves whether Equation (2) offersa similar breakdown of the number of pertinent partieswhen the election is held under the extremely personalizedcontext of Colombia’s 2002 election. The super-proportionality feature of SNTV implies that the exponentshould be, theoretically, higher than 0.5 that Taageperafound for PR systems. We could posit that the exponentmight be 0.75, which is the average of 0.5 (the expectationfor PR) and 1 (the theoretical upper limit, by which everyseat in a district is won by a different party). Exploration ofthis for Colombia’s 2002 election (not shown) revealed thatthis was close to accurate.xv So if the term,M:75, in Equation(2) approximates the pre-reform number of seat-winningparties, perhaps the other term, 0.5M, signifies the numberof pertinent losing parties that enter the race. If so, that theterms are in reversed order (when we multiplied Equation(1) by :5M:5, as discussed above) is consistent with ourexpectation that the reform from SNTV to list PR wouldresult in a mirror image of the two dimensions of compe-tition. We explain now what we mean by this, and theimplications it has for the task of our next section, which isto explore competition on the intra-party dimension.

As we sketched above in Section 3, we assume thataspirants for legislative office choose to enter the race in

xv The best fit would be around 0.81, which is a minor deviation from 0.75.

xvi The variable is denoted L, for “loser’s ratio,” with a subscript for therank of loser being evaluated.

xvii In our Bogotá example above, we noted that some small parties hadmore than one candidate, only one of whom was remotely competitive.

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a party where they will be one of two or more competitivecandidates (an intra-party strategy) or the dominantcandidate on a separate party (an inter-party strategy),depending on the incentives offered by the electoral rules.We noted that as district magnitude becomes large underSNTV, a distinct party label that appeals to even a verysmall share of voters may be sufficient to win a seat. Thusthere are many parties that are essentially the campaignvehicle for an individual candidate. That there could be asmany as 0.5M pertinent losers, per Equation (2), reinforcesthe atomization that is represented by a party systemmadeup of so many very small parties. Yet at low magnitude,Equation (2) reminds us that the number of pertinent losersis not much greater than the number of seat-winners. Infact, at M ¼ 2, Equation (2) predicts 2.68 pertinent parties:1.68 seat-winners and 1 pertinent loser. The actual aver-ages are 1.67 and 1.33.

Returning to Equation (1) and the list-PR election, wesee that, in the larger districts, many aspirants for legisla-tive office apparently enter on a smaller number of perti-nent party lists, relative to the pre-reform system, becausethe number of pertinent losing parties rises much lesssteeply with magnitude than does the number of seat-winners (as well as much less steeply than either quantityrose under the pre-reform system). This dynamic repre-sents the phenomenon of party mergers following thereform, as we posited: fewer parties that are effectivelyvehicles for one candidate’s cultivation of his or herpersonal vote, but a greater tendency for parties to containmultiple competitive candidates on their lists. Or, to put itanother way, after the reform in large districts, more losingbut competitive candidates are losing on the intra-partydimension rather than the inter-party, by being on the listsof seat-winning parties rather than running in separateparties. At smaller magnitudes, Equation (1) reflects theparty splits that we posited we would see as candidateswho formerly differentiated themselves by competingunder the banner of one party label–when their personalvotes accrued only to themselves–now differentiatethemselves on separate party lists.

As for Nv, the model in Table 3 shows a similar impact ofreform, with a near doubling of the intercept, but a signifi-cantly lower slope. Thus, much like the number of pertinentparties, fragmentation based on votes cast rises at lowermagnitudes and falls at higher magnitudes, relative to thepre-reform personalized system.

The findings of this section, then, are remarkable.Focusing on our primary outcome variable, the number ofpertinent parties, we were able to uncover a systematicrelationship to district magnitude in the two differentelectoral systems. We suggested that the number of perti-nent parties, both seat-winners and also rans, depends onthe strategic incentives of legislative aspirants to enter onan existing party label (an intra-party strategy) or a newparty (an inter-party strategy). However, in order todetermine whether our logical basis behind the patternsdepicted by Equations (1) and (2), is valid, it is obviouslyessential that we explore the intra-party dimension. Arewecorrect to say that the decline in both seat-winners andpertinent losing parties under list PR at higher M isaccompanied by an increase in intra-party competitiveness,

compared to the former system? Are we right that intra-party competition was greater at lower magnitudes underthe former system, and that it declines after a change toparty-list competition? We will have successfully con-nected the two dimensions of competition only if we canfind evidence that the answers to these questions are in theaffirmative, possibly paving the way towards a morecomplete logical model (Taagepera, 2008) of how electoralsystems operate on the two dimensions of representation.We explore the evidence from the intra-party dimension inthe next section.

6. The impact of listization: the intra-party dimension

If our premise regarding the “mirror” effect of the twodimensions is accurate, we should see systematicpatterns of adaptation by individual parties accordingto district magnitude. That is, intra-party competitionshould be more extensive at the lower magnitudes underSNTV, but at the higher magnitudes following a changeto open-list PR.

To explore intra-party competitiveness, we look first atthe propensity of parties to present either open or closedlists, taking advantage of this unique feature of Colombia’snew system. Then we consider the degree of actualcompetitiveness of both the post-reform open lists and thepre-reform parties. For the latter task, we define a first-loserratio, or L1, as the votes for each party’s first losing candi-date divided by the votes of its last winning candidate.xvi

The ratio, L1, would equal 1.0 if there were a tie for a par-ty’s last seat. It would be zero if losing candidates of theparty won no votes. The latter theoretical possibility drawsour attention to strategic choices that parties make, undereither SNTV or list-PR systems, for there are outcomesunder both SNTV and list-PR that are effectively L1 ¼ 0,resulting from conscious efforts to restrict intra-partycompetition. Under SNTV, such an effort comes fromlimiting the number of endorsed candidates to one, whileunder list PR it comes from the decision to adopt a closedlist.

The personalization of SNTV allocation implies thatsome parties may seek to nominate not more than they canrealistically elect. This situation is equivalent to one inwhich a party has a first-loser who won zero votes. Alter-natively, a party may nominate more than it can elect, butthen intervene in the campaign (Swindle, 2002), seeking toconcentrate its votes on an electable subset of its candi-dates.xvii Our notion of the “mirror image” of the twodimensions of competition suggests that this strategy ofrestricting intra-party competition through nominationcontrol and campaign intervention should be most preva-lent at higher magnitudes, where inter-party strategies arewidely employed: many entrants who are the solecompetitive candidate of their party. Such parties will

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exhibit first-loser ratios at or near zero. We shall test thisexpectation below.

Similarly, presenting a closed party list is obviouslya means to prevent intra-party competition. In a closed list,the first loser has obtained no votes. Of course, so have allcandidates, including thewinners; however, if we attributedpreference votes to candidates on closed lists, sensibly allvoteswould be attributed to thewinning candidates. Indeed,on closed lists that elect only one candidate, there is littledifference between the actual closed list and a hypotheticalopen list in which one candidate obtained 100% of prefer-ence votes. In other words, under list PR, the most personal-ized parties may be those that present closed lists. This isa surprising claim, in that closed lists are generally assumedto be conducive to cultivating a party reputation (e.g. Careyand Shugart, 1995). In the analysis that follows, we firstexplore the patterns of choice of list type, and then turn ourattention to first-loser ratios under SNTV and open lists.

6.1. Open or closed lists and personalization

To consider whether the closed lists presented inColombia in 2006 were indeed personalized, we willexplore the choices of parties running incumbent legisla-tors. Incumbency is typically a key asset in personal vote-seeking (Cain et al., 1987). We hypothesize that closed liststypify parties born of party splits where an incumbent facescompetitors (possibly including other incumbents) onother lists. Closed lists likewise could be the choice ofparties running on the personal reputation of someonewho is not a candidate in the district, for instance a Houselist associated with a Senate candidate or one associatedwith a presidential candidate or other national personality.A closed list deemphasizes the characteristics of multiplecandidates on the list and facilitates highlighting either thelist head or the national leader. On the other hand, partiesthat form from mergers, which thereby combine candi-dates (possibly including incumbents) from two or morepre-existing parties should present open lists. The poolingof votes across several candidates signals to the electoratethe coordination and cooperation of formerly distinctparties, because a vote for any of them potentially helpselect others.

These hypotheses regarding list type challenge existingunderstanding of intra-party competition, whereby closedlists are seen to encourage the articulation of a party’s

Table 4List type and incumbency, by district magnitude.

District magnitude No. of districts(and members)

No. of pertinentparty lists

No. (and percent)of pertinentclosed lists

2 12 (24) 56 29 (51.8)3–4 7 (25) 35 3 (8.6)5–7 11 (64) 65 3 (4.6)13–17 2 (30) 15 0 (0.0)18 (Bogotá) 1 (18) 13 4 (30.8)House summary 33 (161) 184 39 (21.2)Senate 1 (100) 14 4 (28.6)

a Each category so marked includes one case in which two members were elecsole candidate elected from their list.

b Includes 13 incumbents who ran on open lists that failed to elect anyone.

reputation for programmatic policy, while open listsemphasize the personal reputations of individual candi-dates (Carey and Shugart, 1995). We do not claim that thisconventional wisdom is wrong, but rather that it requiresqualification. If a closed list is chosen by an incumbentsplitting from an established party, the closed list may belittle different from a “personal list” in that it is simply thatincumbent’s reelection vehicle. On the other hand, while anopen list clearly allows its candidates to differentiatethemselves by emphasizing personal characteristics orconstituency ties, when adopted by parties containingcandidates from two or more formerly separate parties, italso symbolizes their cooperation and thereby promotesa collective party reputation.

Table 4 shows the prevalence of closed lists at variouscategories of district magnitude, along with indications ofhow many incumbent legislators ran and were elected oneach list type. It is immediately evident that open lists weremuch more common than closed, except at the smallestdistricts. Recall that it is precisely in the smallest districtswhere our conception of the mirror image led us to expectthat the increased inter-party competition (seen by the risein the number of pertinent parties, Section 5) would beaccompanied by reduced intra-party competition. Obvi-ously, to the extent that parties are presenting closed listsin small-magnitude districts, we are seeing exactly suchlimitations on intra-party competition.

Overall, only about 20% of the pertinent parties in theHouse presented closed lists and only around 10% ofRepresentatives and two Senators were elected on suchlists. However, in the smallest districts, half the pertinentparties presented closed lists and 40% of the Representa-tives were so elected. All thirteen incumbents who ran, andall eight who were reelected, on closed lists were found intwo-seat districts. The incumbents running on open lists,on the other hand, were found everywhere but the smallestdistricts (with a lone exception).

In the two-seat districts, we see closed party lists thatwere essentially “personal lists.” Most were lists of Liberalincumbents; three of those who were reelected hadswitched to Cambio Radical. Our interpretation of thisphenomenon is that these are popular local politiciansknown for (clientelistic) service to the district, but whonowneed to demonstrate being on the side of the presidentto ensure continuing ability to deliver. Hence, in the 2006legislative election, which occurred eleven weeks before

No. of members(and percent)elected on closed lists

Incumbents heading(and elected on)closed lists

Incumbents running(and elected) onopen listsb

10 (41.7) 13 (8) 1 (1)3 (12.0)a 0 10 (6)2 (3.1)a 0 33 (19)0 (0.0) 0 14 (8)2 (11.1)a 0 8 (6)

17 (10.6) 13 (8) 66 (40)2 (2.0) 0 62 (46)

ted from a single closed list; all other members from closed lists were the

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Uribe’s own reelection, they changed to a new, pro-Uribe,label. Other incumbents kept the Liberal label to emphasizetheir opposition to Uribe. While politicians with competingallegiances to presidential candidates could have run (andoften did so) on a shared label under the purely personal-ized SNTV, after electoral reform they had strong incentivesto differentiate themselves on separate lists–inter-partycompetition displacing intra-party. That the lists wereclosed made these lists effectively vehicles only for theelection of the candidate ranked in the number-one slot–inthis case an incumbent in each competing list.

Several of the other pertinent parties presented closedlists to emphasize the personal reputation of a well-knownpolitician. Therewere at least three such parties, associatedwith politicians based in Bogotá: Carlos Moreno de Caroxviii

and two ex-mayors, Enrique Peñalosaxix and AntanasMockus.xx Each of these lists could hardly be more“personalized”; the closed list allowed the party to down-play the identity of the candidates actually on the list andemphasize the extra-list leader. Peñalosa’s list elected twoRepresentatives in Bogotá, but otherwise these closed listswere unsuccessful. Indeed, as Table 4 reveals, the successfulparties outside of the smallest districts almost always hadopen lists, many of which contained multiple incumbents.Even defeated incumbents were often important to theirparty’s success, having contributing their personal vote totheir list’s pooled total (as in the example from Valle inSection 3.2).

6.2. First-loser ratios in SNTV and OLPR

Now we turn our attention to the first-loser ratios,comparing SNTV in 2002 to OLPR in 2006. We expect highcompetition (L1 approaching 1.0) where two conditions arepresent: (1) estimating the precise number of seats a partywill win is difficult, and (2) intra-party votes pool to theparty as a whole. Estimating the number of seats a partymay win is most difficult under high magnitude (Cox, 1997:103–6), meaning parties may have at least s þ 1 viablecandidates (and hence a strong first loser). That votes poolto the list implies that the party has no reason to interveneand either restrict endorsements or attempt to reducevotes going to candidates other than the subset it deter-mines are its most viable seat-winners. Thus we havea hypothesis: the higher the magnitude, the closer the L1approaches 1.0, if the system is OLPR.xxi

If high-M OLPR is the combination in which the highestvalues of L1 are expected, where might the lower values befound? Under OLPR, if a party’s s can be estimated withreasonable certainty, ambitious candidates will see little togain from joining a list if it already has s viable candidates.

xviii Moreno’s party was called Dejemos Jugar al Moreno; it presented anopen list in the Senate, on which Moreno won 45% of the preferencevotes.xix The party was called Por el País que Soñamos.xx The Senate list for Visionarios con Antanas Mockus was likewiseclosed; Mockus himself was running for president.xxi Means (and standard deviation) for L1: 2002, .51 (0.31); 2006, .60(0.27). The ranges are 0.015–0.991 in 2002 and 0.080–0.997 in 2006.

Because these estimates are easiest at low magnitudes,these are the districts where L1 would tend towards zero.However, when considering that some of these parties mayactually have expectations of winning one additional seat,or information is poor about which of its candidates areviable, some parties (expected to be few in number) mayhave L1 approaching 1. Thus there may be a bimodal rela-tionship for OLPR at low magnitudedsomething we willinvestigate below.

Under SNTV, parties may make an effort to avoid anoverdispersion of their candidates’ votes, given that theirlosers’ votes do not pool to help their more viable candi-dates obtain representation. That is, some parties may havemore candidates running than they can elect, but will havesought to concentrate and equalize their votes on just anelectable subset (L1 near 0). We expect higher L1 at low Mthan at high M under SNTV only because a party that haslocal dominance can attract multiple serious office-seekersand allow them to compete openly, with minimal risk offailing to win one or both seats (in a two-seat district).Otherwise, the personalizing logic of SNTV should lead toL1 being low.

We explore the adaptation of parties on the intra-partydimension now by looking at kernel density estimates offirst-loser ratios in the smallest and largest districts. Ifa kernel density shows a single large peak near 1.0, weknow that the set of parties over which it was estimatedtends to be competitive internally. If, instead, the peak isnearer zero, it indicates internally uncompetitive parties. Adistribution without a single mode indicates variation instrategies within the set being analyzed.xxii

If our expectations about the intra-party dimensionmirroring the inter-party dimension are correct, we shouldexpect the large districtsdwhere the inter-party result waspartymergersdto showa shift towards greater competitionwith the reform. The smaller districts, on the other hand,where the typical inter-party effect was party splits, shouldtend to shift the other direction. Fig. 2 shows that this isindeed the case. In the largest districts (left panel of thefigure), the OLPR election shows a sharp peak near 1.0. Bycontrast, under the former SNTV system the distribution isskewed towards the uncompetitive end. However, in thesmallest districts (M¼ 4 or less), there is somewhat greatertendency for intra-party competitiveness under the SNTVelection than therewas after the shift to OLPR. The open-listdistribution is moderately bimodal, indicating some partieswere internally competitive, while many were not.xxiii

The kernel density estimates thusprovide support forourexpectation that changes on the two dimensions would

xxii To avoid biasing results in our favor, we have dropped from theanalysis those parties that had no losing candidates (which wouldexaggerate the lower range of L1). Thus our results refer only to partiesthat actually nominated more than s candidates, so we can see whetherlosing candidates were competitive.

xxiii Kernel density estimates of the medium magnitudes, not shown,reveal little change from SNTV to OLPR. This also mirrors the inter-partydimension, where these districts were those with no significant change inthe number of parties.

Fig. 2. Kernel density plots of first-loser ratios by large and small magnitude.

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660 659

mirror one another: where inter-party competitiondecreased throughpartymergers (largedistricts), intra-partycompetition increased; where inter-party competitionincreased (small districts), intra-party competition tended todecrease. Thus the analysis of patterns of competitionwithinindividual parties confirms the logical model outlined in oursectionon the inter-partydimension (Equations (1) and (2) inSection 5). Therewe explained the number of pertinent vote-earning parties based on the joint impact of districtmagnitude on the number of seat-winning parties and ofpersonalization versus listization on the tendency of addi-tional aspirants to enter on existing parties or newones.Herewereportedevidenceat the levelof seat-winningparties, andsaw that the two dimensions indeed mirror one another intheir relationship of competition to magnitude.

7. Conclusions

Our analysis leveraged a rare case of change in electoralformula with no accompanying changes in districting, andanalyzed impacts on both the inter-party and intra-partydimensions. Although we considered only a single post-reform election, our findings offer some insights intopossible longer-term consequences that are of interest toscholars and practical reform advocates alike. In thisconcluding section, first we address some implications forColombia itself, and then for the field of comparativeelectoral systems.

Advocates of Colombia’s electoral reform had as one oftheir goals a reduction in the tendency of many smallparties to be little more than personal campaign vehicles(Pizarro, 2001; Santana, 1998; Shugart et al., 2007). Theresults of the first post-reform election suggest they suc-ceeded, in that the number of pertinent parties in largerdistricts has been reduced sharply, as has the effectivenumber of parties. Reformers also sought to reduce cli-entelism and corruption, which is a serious issue given

xxiv Dozens of legislators have been under investigation for ties to eitherdrug-trafficking or paramilitary forces. See the regular reports of Con-greso Visible (www.congresovisible.org).

Colombia’s problem with drug-trafficking.xxiv Of course,the success of this goal is much harder to assess, especiallywith one election. Nonetheless, along with the reducednumber of microparties, increased intra-party competitionin the larger districts may help. Clientelism is most favoredby candidates who have what in Colombia is called the votocautivo (captive vote, as discussed by Leal and Dávila, 1990:35). That is, clientelist politicians tend to carve up theelectorate in such a way that few votes are really “up forgrabs,” with clientelist brokers delivering targeted benefitsto a relatively stable electorate (Osterling, 1989: 164).

Some scholars have seen open lists and high districtmagnitude as facilitating clientelism, as well as corruption(Chang and Golden, 2007). Yet we saw that, relative toSNTV, open lists have a beneficial party-building effect thatis often overlooked in the literature. The basic impact oflistization is that votes cast for one candidate on a list mayassist the election of others, reducing the certainty of thebeneficiary of an exchange upon which clientelismdepends, as long as the list has competitive candidatesbeyond the expected seat-winners. In the smaller districts,on the other hand, the increased inter-party competitionmay also prove helpful for reformers’ goals. It is true thatwe showed that competing parties in small districts tend tobe relatively uncompetitive internally, and many of themmay be using labels that signify clientelistic ties to nationalleadership. Still, the mere presence of competing partylabels should be salutary in the ability they give voters toaffect the partisan balance in congress. Under SNTV, wherethe viable competitors in small districts often were of thesame party, this opportunity did not exist. The impact ofdifferent systems on clientelism remains an underdevel-oped area of comparative electoral studies. Future analysisof the impact of the Colombian reform over a sequence ofelections may assist this research agenda.

We caution that the “incentive to cultivate a personalvote” is not directly related to intra-party competition, asoften assumed. Our results show that party-vote incentivesare clearly enhanced at high district magnitude by thechange from SNTV to open-list PR. Yet these parties havegreater intra-party competition than was the case beforereform. On the other hand, in small districts, many of thecompeting parties function essentially as campaign

M. Pachón, M. Shugart / Electoral Studies 29 (2010) 648–660660

vehicles of individual candidates, many of whom run at thehead of closed listsdthe list type usually understood toenhance party-vote cultivation. Thus our findings suggesta need to unpack the concepts that have heretofore guidedresearch on personal vote incentives of electoral systems.

Our analysis of the Colombian case has suggested a linkbetween the inter-party and intra-party dimensions thatcould be theoretically useful beyond this case. Underpersonalistic systems, we showed, additional aspirants foroffice are more likely to enter on existing parties in smallerdistricts, but on their own new parties in the large districts.However, after listization, we confirmed our theory ofa “mirror” effect, inwhich small districts tended to see partysplits (with less intra-party competition resulting) but partymergers occurred in large districts (resulting in increasedintra-party competition). The findings of this case thussuggest that in evaluating the effects or reform, or proposingactual electoral reforms, scholars and practitioners need tobe cognizant of how the two dimensions of competition,inter-party and intra-party, are tied to one another.

Acknowledgments

We thank Royce Carroll, Scott Desposato, Joel Johnson,Santiago Olivella, Flavio Reyes, Rein Taagepera, and theanonymous reviewers for Electoral Studies for commentsand advice. Professor Shugart acknowledges support fromthe National Science Foundation, grant SES-0452573.

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