## Aggregate uncertainty, framing effects, and candidate entry

##### Permanent Link

http://hdl.handle.net/2144/19570##### Abstract

This dissertation studies how different voter characteristics and electoral rules affect the incentives and decisions to seek political office. The focus is on generalizing standard approaches to observed differences in the runoff rule and incorporating more accurate descriptions of voter behavior which may not be fully rational. In each chapter, I consider a model of strategic entry by candidates for office in democratic elections.
In the first chapter, I incorporate the observed differences in thresholds for first-round victory in a model of runoff elections. The set of equilibria varies substantially with the threshold, indicating that the 50 percent threshold used in most models is not innocuous. The set of equilibria immediately contains equilibria that were thought to exist only under plurality rule, whereas for thresholds above 50 percent, there is no change in the set of equilibria. Additionally, for any threshold under one half, there exist equilibria in which a candidate who loses with certainty still chooses to run. The set of two candidate equilibria is invariant to all thresholds under one third, and the set of multicandidate equilibria is invariant to all thresholds above one half.
In the second chapter, I introduce aggregate uncertainty by making candidates unsure of the distribution of voter preferences in the electorate. The set of three candidate equilibria expands and equilibrium platforms become more diverse. This provides a theoretical basis for Duverger’s Hypothesis. Equilibria also feature two common empirical phenomena. For instance, some candidates choose to enter despite losing with certainty in equilibrium. Also, in some equilibria, a Condorcet winning candidate (a candidate who would win every pairwise election) fails to win the election.
In the third chapter, I generalize the citizen-candidate model to a multidimensional setting and characterize the set of equilibria. I later incorporate two well-documented violations of the Weak Axiom of Revealed Preference in a model of plurality elections: the compromise and attraction effects. Entry by an extreme candidate may shift the frame of reference for some voters in ways which favor particular moderate candidates. Incorporating these preferences generate equilibria in which extremist candidates enter plurality elections in order to attractively frame their preferred moderate, even if the extremist has probability zero of obtaining office themselves.