Conformity and truthful voting under different voting rules

Abstract

We induce conformity in a binary-decision voting game in which one of the options require certain support (majority, supermajority or unanimity) to be the adopted decision. We consider heterogenous types of voters in that each of them prefer a different outcome in the voting game. We demonstrate theoretically that truthful voting is the unique equilibrium without conformity for each possible voting rule. Introducing conformity enlarges the set of equilibria, which includes voting profiles in which agents do not necessarily vote for their preferred option. If we account for the presence of non-conformist honest voters that vote truthfully for their preferred option, truthful voting is more pervasive for conformist voters in equilibrium. In our setting, the effects of conformity and honest voters on the likelihood of voting truthfully depend on the voting rule that determines whether or not voters are in a decisive group to implement one of the decisions. We provide empirical support for our theoretical predictions by means of a laboratory experiment. Our findings indeed suggest an interplay between the voting rule and the willingness to conform.