Approval Voting: Economic Theory and Experimental Evidence

• Applicant: Professor Dr. Carlos Alós-Ferrer
• Subject Area: Economic Theory
• Term: from 2012 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 214951190

• Final Report Year: 2024

Final Report Abstract

Currently-employed voting methods, mostly based on Plurality Voting, are known to misrepresent the preferences of the electorate (because voters can only express their maximum) and create many paradoxical and socially-undesirable phenomena, as the election of candidates despised by an absolute majority. Approval Voting is an alternative voting method where voters can approve of as many candidates as they wish, and the candidate with the most approvals win. It has been argued that this method avoids “wasted vote” effects, favors the election of compromise candidates, and elicits less strategic behavior (misrepresenting preferences to manipulate results) from voters. This project examined Approval Voting both theoretically and experimentally. Theoretical results have shown that Approval Voting is non-manipulable in the sense that voters always have a strongly sincere best response (a best response ballot such that every approved candidate is strictly preferred to every disapproved one) given other voters’ ballots. Further, Approval Voting data can be used to provide a reliable snapshot of political preferences in an electorate, which reveals a highly-multidimensional space when using German data. The project has also examined the properties and stability of Approval Voting in a series of experiments. Those show that Approval Voting favors the election of compromise alternatives (e.g. in terms of equality or efficiency) compared to Plurality Voting, and that is essentially stable with respect to framing (e.g., “us vs. them”, or gains vs. losses) and psychological pressure, in contrast to other voting methods.

Publications

• Circulant games. Theory and Decision, 80(1), 43-69.
  Granić, Ɖura-Georg & Kern, Johannes
  
• Political space representations with approval data. Electoral Studies, 39, 56-71.
  Alós-Ferrer, Carlos & Granić, Đura-Georg
  
• The problem of the divided majority: Preference aggregation under uncertainty. Journal of Economic Behavior & Organization, 133, 21-38.
  Granić, Đura-Georg
  
• Strongly sincere best responses under approval voting and arbitrary preferences. Games and Economic Behavior, 117, 388-401.
  Alós-Ferrer, Carlos & Buckenmaier, Johannes
  
• The Role of Payoff Valence on Voting: Egalitarian for Gains and Selfish for Losses. Frontiers in Psychology, 12.
  Alós-Ferrer, Carlos; Garagnani, Michele & García-Segarra, Jaume
  
• Voting for Compromises: Alternative Voting Methods in Polarized Societies. SSRN Electronic Journal.
  Alos-Ferrer, Carlos & Buckenmaier, Johannes
  
• Voting under time pressure. Judgment and Decision Making, 17(5), 1072-1093.
  Alós-Ferrer, Carlos & Garagnani, Michele
  
• The framing of elections: cooperation vs. competition. Social Choice and Welfare, 65(2), 363-385.
  Alós-Ferrer, Carlos; Garagnani, Michele & García-Segarra, Jaume