Electoral Incentives and Electoral Systems: Five Advantages of Two Party Systems

• In Event: Dispersed Representation and its Discontents

Abstract

Multiparty systems are often defended as better than two-party ones because they give voters a wider array of choice, thereby enhancing representativeness. Skeptics respond that this ignores the government-formation stage. Unpredictable at the time of the election, it can over-represent small parties. This has led to a rich debate about the optimal number of parties from the perspective of voters. Here we focus instead on the incentives confronting candidates for office in the two systems. We adduce five reasons to think that two-party competition is better. (i) Candidates in winner-take-all contests must appeal to as broad an array of voters as possible, making it more likely that they will internalize the costs of the deals they make to hold parties together, as opposed to post-electoral coalitions whose incentive is to externalize those costs onto outsiders. (ii) In bundling issues into the platforms they run on, candidates in winner-take all contests must discount everything they propose by everything else they propose, decreasing their incentive to accede to disproportionate demands from strategically essential partners. (iii) By analogy to the differences between compromise-based versus last-best-offer arbitration in industrial settings, we argue that candidates in two-party contests have fewer incentives to misrepresent their positions for tactical reasons. (iv) As a government-in-waiting, the opposition party in a two party system has stronger incentives to offer voters a coherent programmatic alternative to the ruling party than does the disparate array of opposition parties in a multiparty legislature. (v) Governments in two-party systems expect to run for re-election, whereas the future partners of parties in coalition governments are unknown. This diminishes their incentive to pursue policies that are good for the country in the medium run.

Authors

• Ian Shapiro, Yale University

• Frances McCall Rosenbluth, Yale University