Strategic vote trading in power sharing systems

Abstract

This paper studies decentralized vote trading in a power sharing system that follows the rules of strategic market games. In particular, we study a two-party election in which prior to the voting stage, voters are free to trade votes for money. Voters hold private information about both their ordinal and cardinal preferences, whereas their utilities are proportionally increasing in the vote share of their favorite party. In this framework, we prove generic existence of a unique full trade equilibrium (an equilibrium in which nobody refrains from vote trading). Moreover, we argue that vote trading in such systems unambiguously improves voters' welfare.