Party Polarization Under Costly Voting

A Kellogg Work-in-Progress Seminar with Faculty Fellow Tom Mustillo.

Mustillo will present his paper that develops computational models of party competition to understand the influence of costly voting on party polarization. Costly voting is broadly construed to include barriers to participation and the costs associated with becoming informed and making choices. Most previous analytic and computational approaches to the study of party competition assume no cost and full turnout. But costly voting will induce some voters to abstain. When the cost of voting increases, who abstains? Indifferent voters who examine the parties and find little benefit to one over another, or alienated voters whose preferences lie far from any party options? In the face of abstention, how do parties adapt? Mustillo models citizen turnout using a utility function that compares their evaluation of party positions against the cost of voting. The main finding is twofold: In party systems with few parties (as in systems using plurality electoral rules), party polarization increases with the cost of voting. In party systems with many parties, party polarization declines with the cost of voting. The mechanism behind these findings pertains to the patterns of abstention that arise from the combination of (a) costs and (b) the number of parties. In small party systems, costly voting induces citizens near the extremes of the policy space to abstain, which in turn allows parties to diverge from the median voter in their search for votes. By contrast, in large party system, costly voting induces higher levels of abstention closer to the median voter, and thereby enables parties to moderate their positions as they hunt for votes.