Date Added: Aug 2010
The authors develop a competitive equilibrium theory of a market for votes. Before voting on a binary issue, individuals may buy and sell their votes with each other. They define the concept of Ex Ante Vote-Trading Equilibrium, identify weak sufficient conditions for existence, and construct one such equilibrium. They show that this equilibrium must always result in dictatorship and the market generates welfare losses, relative to simple majority voting, if the committee is large enough. They test the theoretical implications by implementing a competitive vote market in the laboratory using a continuous open-book multi-unit double auction.