Do American Midterm House Electors Coordinate ?

Do American Midterm House Electors Coordinate? Electors (eligible voters) have been coordinating their turnout decisions and vote choices for the House of Representatives in recent midterm elections. Coordination is a noncooperative rational expectations equilibrium among electors. The theory allows some electors not to care about policy and admits House districts in which a candidate is running unopposed. Stochastic choice models estimated using individual-level data from NES surveys of years 1978{1998 support both coordination and a model in which electors act nonstrategically. Parameter estimates for the coordinating model describe policy-moderating behavior, but estimates for the nonstrategic model mostly do not. Both models show that many voters had policy-related incentives to change their votes between presidential year and midterm|enough to produce a midterm cycle in which the President's party usually loses vote share at midterm. Midterm electors have expected the House to dominate the President in determining post-election policy. Do Americans coordinate their electoral choices in midterm congressional elections? Based on empirical tests of a rational expectations equilibrium model of voters' choices among candidates for President and for the House of Representatives, Mebane (2000) argues that there is coordination among voters in presidential elections. The theory introduced by Alesina and Rosenthal (1989; 1995; 1996), which motivates Mebane's analysis, envisions each voter acting according to a uni ed strategy that spans both the presidential and midterm elections. In Alesina and Rosenthal's theory, each voter's rational expectation about what the aggregate of voters will do at midterm constrains the voter's actions during the preceding presidential election. Each voter's strategic action in the presidential year is predicated on the presumption that all voters will act strategically at midterm. From the perspective of such a uni ed theory, a demonstration of coordination in presidential-year voting is incomplete without a comparable demonstration of coordination at midterm. Midterm nonvoters are relevant for several reasons. First is the raw fact that turnout is lower at midterm than in the presidential election, and di erent kinds of people turn out at midterm. Apparent di erences between midterm and presidential election voters may be nothing more than sample selection phenomena. Second, Alesina and Rosenthal's theory uses an exogenous random device, interpretable as turnout variation, to make the election outcomes uncertain; only if the outcome of voting for President is uncertain can the legislative election results change between presidential election and midterm. But, third, it is a question whether the decision whether to vote is also strategic, also coordinated. We consider the population of everyone who is eligible to vote|henceforth, the population of electors. We assume that each elector has the same basic institutional understanding that is attributed to voters in the theories of Alesina and Rosenthal (1995; 1996) and Mebane (2000). Each elector knows post-election policy outcomes are compromises between the positions taken by the President and the Congress, and each elector believes the two political parties push for distinct policy alternatives. 1 In our theory most|not all|electors care about the policy outcomes. An elector may vote for one of the parties or not vote. An elector is acting to moderate policy when the elector chooses what to do based on the idea that, via the institutional structure, the policy outcome will be intermediate between the parties' positions. Following Mebane (2000), three conditions de ne coordination: each elector's strategy for choosing among candidates or not voting is in equilibrium with every other elector's strategy for choosing among candidates or not voting; each elector's beliefs about every other elector's preferences and strategy are compatible with the elector's own strategy; and each elector's beliefs are compatible with every other elector's beliefs. Coordination occurs when each elector makes the best possible assessment of what the election outcome will be and then uses that assessment to act in the way that is most likely to produce the best possible result for the elector. The equilibrium concept in our model is the same as in Mebane (2000): coordination is a rational expectations equilibrium among electors.1 Each elector is able to make an equilibrium strategic choice that is based on accurate expectations regarding the aggregate results of other electors' intended choices. Di erent electors have beliefs about the upcoming election results that are very similar but not exactly the same in equilibrium. As in the model of Mebane (2000), the similarity is a result of common knowledge all electors have, while the di erences are due to private information each elector has. Our equilibrium includes the level of turnout along with the two-party split of votes for House candidates. Our model allows exogenous factors to motivate an elector to vote, so our equilibrium is not necessarily a new solution to the problem of obtaining substantial positive turnout in equilibrium based purely on post-election policy considerations (cf. Hinich, Ledyard and Ordeshook 1972; Enelow and Hinich 1984; Ledyard 1984; Palfrey and Rosenthal 1985). We use National Election Studies (NES) survey data from midterm election years 1978 through 1998 to estimate a stochastic choice model that matches the theoretical model. In both models, di erent electors have di erent ideas about what the parties' policy positions are. Tests based on 2 estimates of the empirical model's parameters support the existence of coordination among House electors in recent midterm years, with most electors acting to moderate policy. We also introduce an empirical model that applies to midterm elections the core idea in the nonstrategic theory that Fiorina (1988; 1992, 73{81) introduced to describe institutional balancing by voters in elections during presidential years. Mebane (2000) nds the nonstrategic theory to be signi cantly inferior to his coordinating theory in analysis of NES data from the presidential-year elections of years 1976{1996. We nd our nonstrategic model to have implications for midterm elector behavior that are very similar to the implications of our coordinating model. Alesina and Rosenthal's (1989; 1995; 1996) theory implies that the party that wins a presidential election will usually lose support in Congress at midterm. Each voter chooses a congressional candidate during the presidential-year election to match the voter's expectation regarding the presidential outcome, which is uncertain. For some voters, the congressional votes cast when the presidential outcome is uncertain are not the votes they would have cast had they known which presidential candidate would win. At midterm such voters change their votes, so that the midterm election results di er from the congressional results in the preceding presidential-election year. Usually the changed votes reduce support for candidates of the President's party. Alesina and Rosenthal (1989; 1995, 137{160; Alesina, Londregan and Rosenthal 1993) show patterns in aggregate data that match the kind of midterm cycle that their theory implies. No evidence has been presented to show that individual midterm voters act the way the equilibrium of their theory says they should. We examine whether a nonstrategic model of individual electors' choices can explain a midterm cycle pattern as well as a coordinating equilibrium model can. Alesina and Rosenthal's theory is not the only one on o er to explain the frequently observed midterm cycle (Erikson 1988). Some have emphasized the connection between evaluations of the President and midterm election outcomes. Put most simply, as the President's popularity goes, 3 so goes the midterm election (Kernell 1977; Piereson 1975; Born 1990; Cover 1986; Abramowitz 1985). Such explanations are not strictly speaking alternatives to a policy-moderating theory, because evaluations of policy performance may be a large reason for a President to be more or less popular. Another line of argument emphasizes di erences in voter turnout between the presidential election and midterm, with a surge of support for the President's party in the presidential election ebbing at midterm (Campbell 1966; Campbell 1985, 1987, 1991; Born 1990; Cover 1986). The relationship between partisan preferences and turnout at midterm is well known to be strong, as we recon rm in our empirical analysis. We are not currently able to assess how surge-and-decline dynamics may a ect midterm cycles in the context of a coordinating equilibrium, because we do not have a comparable analysis of elector's choices in presidential years. In a manner similar to Mebane (2000), the model of coordination we develop is based on a xedpoint theorem that de nes the common knowledge belief that all electors have about the upcoming election results. The values of two aggregate statistics summarize the election results: (i) the proportion of the two-party vote to be cast nationally for Republican candidates for the House and (ii) the proportion of electors who will vote. Our theory di ers in a basic way from Mebane's by including electors whose election-time preferences do not depend on post-election policies. The strategies of such electors do not depend on the aggregate values. Each elector who does care about the policies responds to the belief each has about the aggregate values, because the values a ect the loss each expects. Notwithstanding their di erent election-time interests in the aggregate values, in our theory all electors have the same common knowledge belief. We also allow some House districts to have a candidate running unopposed. As in Mebane (2000), the xed-point values determined in the empirical analysis estimate the aggregate values tha