Democracy undone. Systematic minority advantage in competitive vote markets

• 成果类型: Article
• 署名作者: Casella, Alessandra; Turban, Sebastien
• 署名单位: Columbia University; National Bureau of Economic Research; Center for Economic & Policy Research (CEPR); California Institute of Technology
• 刊物名称: GAMES AND ECONOMIC BEHAVIOR
• ISSN/ISSBN: 0899-8256
• DOI: 10.1016/j.geb.2014.07.002
• 发表日期: 2014
• 页码: 47-70
• 关键词: Voting; Majority Voting; Markets for votes; Vote trading; competitive equilibrium

摘要

We study the competitive equilibrium of a market for votes where the choice is binary and it is known that a majority of the voters supports one of the two alternatives. Voters can trade votes for a numeraire before making a decision via majority rule. We identify a sufficient condition guaranteeing the existence of an ex ante equilibrium. In equilibrium, only the most intense voter on each side demands votes, and each demands enough votes to alone control a majority. The equilibrium strongly resembles an all-pay auction for decision power: it makes clear that votes are only a medium for the allocation of power. The probability of a minority victory is always higher than efficient and converges rapidly to one-half as the electorate increases, for any minority size. The numerical advantage of the majority becomes irrelevant: democracy is undone by the market. (C) 2014 Elsevier Inc. All rights reserved.