OVERVIEW: THE REGIONAL PARTY SYSTEM AND COHESIVE LEGISLATURE IN SOUTH KOREA

Since the transition to democracy, major political parties have had a strong regional support base in South Korea (Cho Reference Cho2000; Choi Reference Choi2012). That is, Gyeongsang Province has been a stronghold for conservative parties, including the Democratic Justice Party (1987–90), the Democratic Liberal Party (1990–5), the New Korea Party (1995–7), the Grand National Party (1997–2012) and the Saenuri Party (2012–present). Jeolla Province has been dominated by liberal parties, including the Party for Peace and Democracy (1987–91), the Democratic Party (1991–5), the National Congress for New Politics (1995–2000), the New Millennium Democratic Party (2000–7), the United New Democratic Party (2007–8), the Democratic United Party (2011–13) and the New Politics Alliance for Democracy (2014–present). Additionally, during most of the post-authoritarian period, right-wing regional champion parties existed in Chungcheong (Mid-South) Province, including the New Democratic Republic Party (1987–90), the United Liberal Democrats (1995–2006), the People First Party (2007–8) and the Liberty Forward Party (2008–12).

Despite the conservative–liberal division, those Gyeongsang, Jeolla and Chungcheong parties also need to deliver local benefits to their supporters in the provinces to maintain their dominance (Shin 2013). Moreover, about 80 per cent of South Korean legislators are elected under the single-member district system, which encourages politicians to deliver narrowly targeted benefits – pork – to their constituents (Lancaster Reference Lancaster1986; Stratmann and Baur Reference Stratmann and Baur2002). Even though the rest of the legislators are elected from nationwide party lists, until the 2000 congressional elections voters had only one vote for a candidate in a single-member district, which determined a party’s seat share from the party list. Since 2004, voters have had two votes – one for a candidate and one for a party; nonetheless, the outcome produced by the party-list component counts for just 20 per cent of all congressional seats. Although a mixed-member electoral system was adopted, the single-member district component is considered far more important than the party-list component in South Korea (see e.g. Brady and Mo Reference Brady and Mo1992; Shin 2011). Due to the regionalized electoral competition and the pork-inducing electoral institution, Korean legislators should have strong incentives to deliver pork rather than policy. Thus, the Gyeongsang–Jeolla divide has been more salient than the conservative–liberal split in the National Assembly (see Hix and Jun Reference Hix and Jun2009).

Another piece of evidence for pork-centric politics in South Korea is that there is little obstructionism in legislative voting. In an extremely pork-centric legislature (such as the Philippine House of Representatives), most bills are passed with few objections because legislators do not pay close attention to policy and tend to vote with the president, who controls access to pork pipelines (see Reference ShinShin Forthcoming). The Korean legislature does not seem very different from this pork-dominant legislature.

Figure 1 shows the proportion of roll-call voted bills and resolutions that received simple majority consent, over 95 per cent consent and unanimous consent, respectively, from the 16th National Assembly during Kim Dae-jung’s presidency (June 2000–February 2003) until the 17th National Assembly during Lee Myung-bak’s (February–May 2008).

Figure 1 Roll-Call Voted Bills and Resolutions in the South Korean National Assembly, 2000–8

The data set includes 3,737 bills and resolutions, of which just 14 were voted down. Particularly in the 16th National Assembly under Kim (n=853) and in the 17th National Assembly under Lee (n=173), all 1,026 bills and resolutions presented on the floor were passed, indicating that the National Assembly faced very little obstructionism in legislative voting (see Appendix, Table A1). More striking is that, although the percentage of bills and resolutions passed with unanimous consent decreased over time, on average, 88.4 per cent of bills and resolutions were passed with over 95 per cent consent. That is, most of the time, the Korean legislators voted affirmatively on bills and resolutions, regardless of whether they were with the president or in the opposition.

Figure 1 also reveals, however, that except for the 16th National Assembly under Kim Dae-jung, more than half of bills did receive at least one negative vote. Who cast these negative votes in this highly cohesive legislature? That is, who would deviate from the preferences of the legislative majority, to deviate from their party majority in legislative voting? The subsequent section suggests a general theory to address these questions.

A THEORY OF LEGISLATIVE VOTING BEHAVIOUR IN REGIONAL PARTY SYSTEMS

In a national party system where major parties are fairly competitive in most areas of the country, parties need to deliver benefits to the broad population, and they thus tend to focus on the delivery of national public policies, or policy. Legislators then have to pass bills in the parliament to deliver policy; thus, party leaders often impose strong discipline on rank-and-file party members to facilitate the passage of bills. Accordingly, party unity in legislative voting tends to be high in such policy-centric contexts (see, e.g., Carey Reference Carey2007). Conversely, in a regional party system, where different parties are dominant in different parts of the country, those regional champion parties should focus more on the delivery of local benefits, or pork, to safeguard their strongholds in the region. In this environment, one might expect party voting unity to be lower, because politicians would pay little attention to policy; thus, party leaders would not need to impose strong discipline frequently in legislative voting.

In contrast to these expectations, however, voting unity within parties (not to mention across parties) should also be high in a pork-centric system, in part because politicians pass just about any bill presented on the floor of the legislature (see Figure 1, also Reference ShinShin Forthcoming). Moreover, when the party leaders do impose discipline over some significant bills, those who are elected in their parties’ regional strongholds are especially unlikely to defect from the party line, because being endorsed by their regional champion party is of critical importance in winning the subsequent election. Furthermore, the legislators who are elected in the parties’ regional strongholds in particular should be far less likely to defect when casting a roll-call vote on legislation that aims to deliver pork to their provinces. Thus, in a pork-centric regionalized setting, party voting unity is expected to be high, just as it is in the policy-centric context, although the mechanisms leading to the outcome differ. To be specific, in a regional party system we expect:

Despite this strong party voting unity, whether a legislator is in the opposition or the ruling party may affect her decision whether to defect. In pork-centric systems, politicians within governing parties may be more disciplined than their counterparts in the opposition, because the former can be granted access to government resources for pork (see Reference ShinShin Forthcoming). Furthermore, in a pork-centric legislature, the government has tight control over the legislative process because few legislators pay close attention to policy. In the National Assembly of South Korea, from 2000 to 2008, for example, about 43 per cent of bills were proposed by the government. Nonetheless, many of the bills proposed by legislators are drafted originally by the government and submitted through the legislators. Even when legislators draft a bill, most of the time the bill can go through a committee only after government agents stationed in its subcommittees have approved it. The government indeed plays a dominant role in making laws in the South Korean regional party system (see, e.g., Park Reference Park1998).

Thus, sometimes opposition legislators who want to deliver policy instead of pork to their constituents may have strong incentives to vote against bills, or to voice their opposition, in the pork-centric legislature controlled by the government. Because the majority of parliamentary members, including the opposition, almost always pass any bill presented on the floor, those opposition legislators voting against bills should appear to deviate from the party majority in legislative voting.

A legislator’s party affiliation, therefore, is expected to have different effects on the legislator’s voting behaviour, depending on her constituents’ demands for pork or policy. The voters’ demands stem mainly from their socioeconomic conditions. For example, well-educated, well-off voters often desire policy over pork (Banfield and Wilson, Reference Banfield and Wilson1963; Scott, Reference Scott1972; Reference ShinShin, Reference Shin2015), so sometimes politicians elected from more developed districts have strong incentives to object to a policy that may conflict with the interests of their constituents (Reference ShinShin Forthcoming). Thus, as the socioeconomic status of constituents rises and they care more about policy than pork, the incentive of opposition legislators to vote against their parties is expected to increase. In contrast to those opposition politicians, members of the governing party should have little incentive to defect from the party majority even when constituents desire policy, because the voters who voted for the president’s party candidate should expect to receive the promised policy (on top of pork) from the president (Shin 2013). Thus, we would expect governing-party members to be even more disciplined in legislative voting when their constituents demand policy.

DATA, MODEL AND MEASURES

To examine legislative voting behaviour in the regional party system, we built an original data set of roll-call votes of all legislators on bills and resolutions in the 16th National Assembly (2000–4) and the 17th National Assembly (2004–8). To test the suggested hypotheses about who would defect from the party majority, we created a dependent variable, Defect _ij , a dummy variable indicating whether legislator i defects from the preference of the party majority when casting a roll-call vote on bill j.² In the National Assembly, an active abstention (pushing the abstention button) is considered an opposition to the bill, because active abstentions count towards the total votes cast, and a bill must receive more than 50 per cent ‘yes’ votes to be passed (see Nemoto Reference Nemoto2009: 214). Thus, we treat an active abstention in the same way as a ‘no’ vote. Defect _ij is coded 1 if a roll-call vote of the legislator differs from those of the party majority; 0 otherwise. Of the observations in the data set, 3.62 per cent are coded 1. Because the dependent variable is binary, we use a logistic regression model as follows.

$$\eqalignno{ {\rm Defect}_{{ij}} \,{=} \,& { \rbeta} _{0} {\plus}\rbeta _{1} \,{\asterisk}\,{\rm Regional}\,{\rm Champion}\,{\rm Party}_{{ij}} {\plus}\rbeta _{2} \,{\asterisk}\,{\rm Pork}\,{\rm Legislation}_{{ij}} \cr & {\plus}\rbeta _{3} \,{\asterisk}\,{\rm Regional}\,{\rm Champion}\,{\rm Party}_{{ij}} \,{\asterisk}\,{\rm Pork}\,{\rm Legislation}_{{ij}} \cr & {\plus}\rbeta _{4} \,{\asterisk}\,{\rm Party}\,{\rm Affiliations}_{{ij}} {\plus}\rbeta _{5} \,{\asterisk}\,{\rm Voter}\,{\rm Demands}_{{ij}} \cr & {\plus}\rbeta _{6} \,{\asterisk}\,{\rm Party}\,{\rm Affiliations}_{{ij}} \,{\asterisk}\,{\rm Voter}\,{\rm Demands}_{{ij}} {\plus}\rbeta _{7} \,{\asterisk}\,{\rm Controls}_{{ij}} {\plus} \it ε_{{ij}} $$

where ε represents the random error term.

EMPIRICAL RESULTS

Table 1 shows model estimations of voting defection in the National Assembly from 2000 to 2008. Overall, they matched our expectations. In the regional party system, politicians who are elected in their parties’ regional strongholds are less likely to defect from the party majority, and the signs on Jeolla and Chungcheong are thus negative and significant. Contrary to our expectation, however, it appears that politicians from Gyeongsang who affiliate with their regional champion party (Grand National Party) are more likely to defect, as the sign on Gyeongsang is positive. Nevertheless, those Gyeongsang legislators are less likely to deviate from their party majority when voting on pork legislation as the signs on Gyeongsang*Pork(Gyeongsang) are negative and significant. Moreover, as voters’ socioeconomic conditions improve, governing-party legislators are less likely but opposition legislators are more likely to defect from the party majority; the coefficients on Education * Government are negative and significant, while those on Education * Opposition are positive and significant.

Table 1 Voting Defection in the National Assembly of the Republic of Korea, 2000–2008

Note: n=294,280; †p<0.10, *p<0.05, **p<0.01; Standard errors in parentheses.

Column 1 of Table 1 displays the impacts of politicians’ affiliations with regional champion parties on their legislative behaviour: legislators of Jeolla parties from their regional strongholds are 1.48 times and their Chungcheong counterparts are 2.18 times less likely to defect from the party majority than are the others. Conversely, legislators of the Grand National Party (GNP) from Gyeongsang are 46 per cent more likely to defect from the party majority. When the affiliations with regional champion parties are interacted with pork legislation, however, those Grand National Party legislators from Gyeongsang are 2.97 times less likely to defect from the party majority when voting on bills that aim to deliver pork to the province (column 2 of Table 1). Although statistically insignificant, Jeolla party legislators from Jeolla are 1.57 times less likely to defect, and Chungcheong party legislators from Chungcheong are 0.82 times more likely to defect when voting on pork legislation for their provinces.

Columns 3 and 4 of Table 1 show the interactive impacts of legislators’ party affiliation and their constituents’ average educational level on the politicians’ legislative voting behaviour. To avoid the multicollinearity problem, the dummy variables for governing-party members and opposition-party members are not included in the same model. The impacts are substantial. An easy way to understand the coefficients is by comparing the legislative behaviour of four hypothetical legislators: one governing-party legislator (G₁₀) and one opposition legislator (O₁₀) from a less developed district where only 10 per cent of voters have received tertiary education beyond high school, and one governing-party legislator (G₆₀) and one opposition legislator (O₆₀) from a more developed district where 60 per cent of the voters have completed some form of tertiary education. G₆₀ is 1.39 times less likely to defect from the party majority than G₁₀,⁵ indicating that legislators with the ruling party become more cohesive in legislative voting as their constituents’ education level increases. Conversely, O₆₀ is 1.26 times more likely to defect than O₁₀,⁶ indicating that legislators in the opposition become less cohesive as constituents’ education level increases.

Models 5 and 6 include both the regional champion party/pork legislation and the party affiliation/voter demands variables. First, regional champion parties influence the probability of voting defection. Jeolla party members in their regional strongholds are 1.31 times and Chungcheong party members in their strongholds are 3.13 times less likely to defect from the party majority, all other things being equal. Politicians in Gyeongsang who are with its regional party (the Grand National Party), however, show little difference in the likelihood of voting defection from the others. Second, voting on pork legislation increases the effects of regional champion party affiliation. When voting on bills to deliver pork, Jeolla party members from their regional strongholds are 1.45 times, and Gyeongsang party members from the province are 4.39 times less likely to defect from the party majority. The interactive effects are not significant for their Chungcheong counterparts, however. Finally, as the education level of voters increases, governing party legislators are less likely and opposition party members are more likely to defect from the party majority, holding other factors constant. For example, the probability of voting defection of a governing-party legislator elected from the more developed constituency (G₆₀) is 40 per cent lower than that of a governing-party member from the less developed constituency (G₁₀), ceteris paribus.⁷ In contrast, among the opposition politicians, O₆₀ is 13 per cent more likely to defect than O₁₀, all else being equal.⁸

Using a Monte Carlo simulation (based on Model 6), Figure 2 shows how an interaction between politicians’ party affiliations and voters’ demands influences the legislators’ voting behaviour. As the average voter’s education level increases and she thus desires more policy than pork, governing-party legislators are less likely, but their opposition counterparts are more likely, to defect from the party line.

Figure 2 Party Affiliations, Voter Demands and Legislative Voting Behaviour

Hence, the gap between the opposition and the governing party widens as the education level increases. In less developed districts, where 20 per cent of voters have received tertiary education, such as Hongcheon and Hwaengsung, for example, the predicted probability of their representatives to defect from the party majority is 4.1 per cent if they are in the opposition; the probability is 3.2 per cent if they are in the president’s party. That is, in the poorer districts the difference in the predicted probability of voting defection between the opposition and ruling party legislators is just 0.9 per cent, which indicates that where voters tend to desire pork over policy, politicians’ legislative behaviour is similar in terms of how likely they are to defect from the party line irrespective of whether they are with the president or not.

It is noteworthy that the party affiliation has considerably greater effects on the probability of voting defection in more developed districts. Where 70 per cent of voters have received tertiary education, such as Gangnam, for example, the disparity in voting defection rate between the opposition and governing-party politicians increases to 2.7 per cent. That difference is statistically significant and also substantial, given that in the highly cohesive legislature politicians defect from their parties only 3.6 per cent of the time. The findings of this analysis thus signify that opposition legislators are far more likely to vote against their parties than governing-party legislators in more developed districts where most constituents are well educated and thus tend to care more about policy.

In addition, the positive signs on the party-list variable deserve attention. Contrary to expectations from the pre-existing studies that show that the legislators elected from party lists are less likely to defect from their parties than are the legislators elected from single-member districts, legislators elected from the Korean party list are more likely to defect, although it is not statistically significant when both the regional champion party/pork legislation and the party affiliation/voter demands variables are included in the models.⁹ Jun and Hix (Reference Jun and Hix2010) also find that party-list legislators are more likely to defect from their parties in the National Assembly, arguing that this is because those party-list legislators tend to seek careers outside the party after their terms end. Another possible explanation would be that since the National Assembly is pork-centric, those party-list legislators are more likely to vote against the preferences of their party majority because they should respond to the interests of the broader population instead of the narrow incentives of their regional strongholds, which would lead them to vote against the pork-centric incentives of their party majority. The result may thus signify that in regional party systems where most politicians strive to deliver pork, the legislators who are elected by the broader population tend to seek policy when on the floor of the legislature, which is consistent with the findings from the pork-dominant legislature in the Philippines (Reference ShinShin Forthcoming).

The negative signs on the three legislative session variables – the 16th National Assembly under Roh, the 17th National Assembly under Roh and the 17th National Assembly under Lee – also deserve special attention. As the reference period is the 16th National Assembly under Kim, the results indicate that legislators were less likely to vote against their parties after Kim Dae-jung’s presidency (1997–2002). Kim was the regional boss whose stronghold was Jeolla Province, while the previous president Kim Young-sam (1992–7) was the head of Gyeongsang Province. Since the exit of those regional bosses, ideology and generational differences have affected voters’ electoral choices to a greater extent (see, e.g., Kim et al. Reference Kim, Choi and Cho2008). Thus, the less frequent party defection by legislators may signify that legislators become more disciplined to follow party ideology and policy in the era of the post-regional bosses.

Finally, because most legislators vote more than once during a legislative session, the observations are not independent. Thus, the results of the logit models are compared with those of fixed-effects logit models, eliminating the dummies for the legislative session fixed effects.¹⁰ The results of both kinds of models are similar, and hence the concern of the non-independent observations can be safely disregarded.