Political Competition in Legislative Elections Snyder (1994)considers a dynamic setting in which heira and Crutzen (2010),Eguia (2011a,2011b)and voters care only about national party positions tha Diermeier and Vlaicu(2011)provide theories of en- are chosen by the party's representatives in the pre- dogenous institution choice leading to powerful par- election legislature to maximize their individual reelec- ties.All these models of the importance of parties in tion chances.In Ansolabehere,Leblanc,and Snyder Congress take the distribution of legislator preferences (2012),a special version of this model,the left and the as exogenously given,while our model provides for right party locate at the 25th and 75th percentile of an electoral model and thus endogenizes the types of the district median distribution.Polborn and Snyder elected legislators. (2017)analyze a model of legislative competition in which only the two parties'national positions matter MODEL for voters and are determined by the median caucus member.Their main focus is on deriving comparative A polity is divided into a set of districts /where #is static predictions about the effects of idiosyncratic (i.e. odd.Each district i contains three strategic agents:a lo- candidate-specific)valence uncertainty and systematic cal Democratic leader.a local Republican leader,and 4 electoral shifts (as in wave elections,where one party a general election median voter. does better in most districts than in previous elections) In the first stage,in each district i,the local leader of on polarization,and testing them empirically.To focus each party P=D,R chooses the position xiP ER of 4 on these comparative static predictions,their model of party P's candidate in district i.The local party lead- candidate competition is much simpler than ours,es- ers can be thought of as a shorthand for the decisive sentially assuming that the local candidates perfectly voter in the respective party's primary election that de- represent the median voter in their respective districts. cides which candidate to nominate.We therefore as- In contrast.our focus is on the effect of the nomina- sume that these local party leaders are not interested in tion process in which candidates are chosen by policy- winning per se,but rather,like any other voter,derive motivated primary voters,who,as we show,generally utility from policy(with details explained below). 4号元 select nominees who are more extreme than the gen- In the second stage,there is a general election in all eral election median voter of the district would prefer districts.In addition to their local candidates'positions. In the influential models of Erikson and Romero each party has a national policy Xp that it can imple- (1990)and Adams and Merrill (2003),voters receive, ment if it receives a majority in the legislature.The na- in addition to the payoff from the elected candidate's tional policy position is not a strategic choice by any position,a "partisan"payoff from his party affiliation, particular player,but rather some aggregate of the po- which,however,is exogenous and orthogonal to his sitions of a party's legislators,discussed further below. policy position.Our model provides a microfoundation The utility of a voter with ideal position 0 from for these partisan payoffs,and shows how they depend district i is on the equilibrium polarization between the parties' candidates in other districts.and how they,in turn,af- g(Xp,x.Q)=-(1-y)Xp-9)2-y(c.o-8)2, fect the candidates'equilibrium positions Probabilistic voting models (e.g.,Lindbeck and (1) Weibull 1987;Dixit and Londregan 1995),as well as differentiated candidates models (DCMs;Aragones where y e(0,1)is the voter's weight on the local rep- and Palfrey 2002:Soubeyran 2009:Krasa and Polborn resentative's position,the policy of the district's elected 2010a,2010b,2012,2014;Camara2012),often con- representative is xi.o,where O[D,R]is the represen- 8 sider an exogenous valence dimension.In the spirit tative's party,and the policy of the majority party P in of the DCM,one can interpret party affiliation in our the legislature is Xp. model as a fixed characteristic,but in contrast to exist- If voters only care about the policy implemented by ing DCMs,voters'preferences over characteristics(i.e., the legislature,then the value of y is zero.There are the candidates'party affiliations)depend on national at least two conceptually distinct reasons why y might party positions and therefore,ultimately,on positions be positive.First,voters may attach an expressive value of candidates in other districts. to their actual vote;that is,a voter may derive utility Our model assumes that national party positions from voting for a local candidate whose position he matter for voters,and a significant number of mod- likes (or opposing one that he dislikes)even if he rec- els explains why this is so.Conditional party govern- ognizes that national policy is determined by national ment theory (Rohde 2010;Aldrich 1995)and endoge- party positions.Second,representatives may have spe- nous party government theory (Volden and Bergman cial influence on policy that is particularly relevant for 2006;Patty 2008)argue that party leaders can use in- their district,for example,through funding projects in centives and resources to ensure cohesiveness of their their district whose payoffs depend on ideology.Note party.Procedural cartel theory (Cox and McCubbins that the case where each election is completely inde- 2005)argues that party leadership can at least en- pendent of what happens in the rest of the country(i.e., force voting discipline over procedural issues.Castan- where literally "all politics is local"and nobody cares about national legislation)corresponds to y =1. Halberstam and Montagnes(2015)provide empirical evidence of spillovers from national presidential campaigns on Senate elections 7 In principle,we could also allow for y to vary between districts, and the positions of candidates in those elections. and all of our results would generalize(with y being replaced by yi 811Political Competition in Legislative Elections Snyder (1994) considers a dynamic setting in which voters care only about national party positions that are chosen by the party’s representatives in the pre￾election legislature to maximize their individual reelec￾tion chances. In Ansolabehere, Leblanc, and Snyder (2012), a special version of this model, the left and the right party locate at the 25th and 75th percentile of the district median distribution. Polborn and Snyder (2017) analyze a model of legislative competition in which only the two parties’ national positions matter for voters and are determined by the median caucus member. Their main focus is on deriving comparative static predictions about the effects of idiosyncratic (i.e., candidate-specific) valence uncertainty and systematic electoral shifts (as in wave elections, where one party does better in most districts than in previous elections) on polarization, and testing them empirically. To focus on these comparative static predictions, their model of candidate competition is much simpler than ours, es￾sentially assuming that the local candidates perfectly represent the median voter in their respective districts. In contrast, our focus is on the effect of the nomina￾tion process in which candidates are chosen by policy￾motivated primary voters, who, as we show, generally select nominees who are more extreme than the gen￾eral election median voter of the district would prefer. In the influential models of Erikson and Romero (1990) and Adams and Merrill (2003), voters receive, in addition to the payoff from the elected candidate’s position, a “partisan” payoff from his party affiliation, which, however, is exogenous and orthogonal to his policy position.Our model provides a microfoundation for these partisan payoffs, and shows how they depend on the equilibrium polarization between the parties’ candidates in other districts, and how they, in turn, af￾fect the candidates’ equilibrium positions. Probabilistic voting models (e.g., Lindbeck and Weibull 1987; Dixit and Londregan 1995), as well as differentiated candidates models (DCMs; Aragones and Palfrey 2002; Soubeyran 2009; Krasa and Polborn 2010a, 2010b, 2012, 2014; Camara 2012), often con￾sider an exogenous valence dimension. In the spirit of the DCM, one can interpret party affiliation in our model as a fixed characteristic, but in contrast to exist￾ing DCMs, voters’ preferences over characteristics (i.e., the candidates’ party affiliations) depend on national party positions and therefore, ultimately, on positions of candidates in other districts. Our model assumes that national party positions matter for voters,6 and a significant number of mod￾els explains why this is so. Conditional party govern￾ment theory (Rohde 2010; Aldrich 1995) and endoge￾nous party government theory (Volden and Bergman 2006; Patty 2008) argue that party leaders can use in￾centives and resources to ensure cohesiveness of their party. Procedural cartel theory (Cox and McCubbins 2005) argues that party leadership can at least en￾force voting discipline over procedural issues. Castan- 6 Halberstam and Montagnes (2015) provide empirical evidence of spillovers from national presidential campaigns on Senate elections and the positions of candidates in those elections. heira and Crutzen (2010), Eguia (2011a, 2011b) and Diermeier and Vlaicu (2011) provide theories of en￾dogenous institution choice leading to powerful par￾ties. All these models of the importance of parties in Congress take the distribution of legislator preferences as exogenously given, while our model provides for an electoral model and thus endogenizes the types of elected legislators. MODEL A polity is divided into a set of districts I, where #I is odd. Each district i contains three strategic agents: a lo￾cal Democratic leader, a local Republican leader, and a general election median voter. In the first stage, in each district i, the local leader of each party P = D, R chooses the position xi,P ∈ R of party P’s candidate in district i. The local party lead￾ers can be thought of as a shorthand for the decisive voter in the respective party’s primary election that de￾cides which candidate to nominate. We therefore as￾sume that these local party leaders are not interested in winning per se, but rather, like any other voter, derive utility from policy (with details explained below). In the second stage, there is a general election in all districts. In addition to their local candidates’ positions, each party has a national policy XP that it can imple￾ment if it receives a majority in the legislature. The na￾tional policy position is not a strategic choice by any particular player, but rather some aggregate of the po￾sitions of a party’s legislators, discussed further below. The utility of a voter with ideal position θ from district i is uθ (XP, xi,Q) = −(1 − γ )(XP − θ ) 2 − γ (xi,Q − θ ) 2 , (1) where γ ∈ (0, 1) is the voter’s weight on the local rep￾resentative’s position, the policy of the district’s elected representative is xi, Q, where Q ∈ {D, R} is the represen￾tative’s party, and the policy of the majority party P in the legislature is XP. If voters only care about the policy implemented by the legislature, then the value of γ is zero. There are at least two conceptually distinct reasons why γ might be positive. First, voters may attach an expressive value to their actual vote; that is, a voter may derive utility from voting for a local candidate whose position he likes (or opposing one that he dislikes) even if he rec￾ognizes that national policy is determined by national party positions. Second, representatives may have spe￾cial influence on policy that is particularly relevant for their district, for example, through funding projects in their district whose payoffs depend on ideology. Note that the case where each election is completely inde￾pendent of what happens in the rest of the country (i.e., where literally “all politics is local” and nobody cares about national legislation) corresponds to γ = 1.7 7 In principle, we could also allow for γ to vary between districts, and all of our results would generalize (with γ being replaced by γ i 811 Downloaded from https://www.cambridge.org/core. Shanghai JiaoTong University, on 26 Oct 2018 at 03:53:05, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0003055418000503