Experimental Evidence on Cooperation, Political Affiliation, and Group Size

Abstract

The main objective of this paper is to strengthen the knowledge about the relationship between cooperation and political affiliation. For this purpose, I carry out an incentivized N-person prisoner’s dilemma experiment. I find that left-wing voters cooperate more than right-wing voters in 3-person prisoner’s dilemmas. However, this difference in cooperation tapers off with group size due to a heterogeneous response to larger decision groups. While leftists cooperate less as the group size increases, I find no significant group size effect for rightists. These findings can partly be explained by differences in beliefs about the cooperativeness of others, but a substantial part remains unexplained.