Doomed to Discord? Electoral Institutions' Effects on Political Divisiveness

In this paper, I employ a game theoretic model to argue that electoral systems affect issue polarization between parties in legislative elections. In majoritarian systems, the winner-take-all nature of electoral competition motivates large parties to fight with each other for votes on issues. Consequently, these large, mainstream parties are more likely to champion for fewer issues, but do so more intensely against each other, i.e., parties are more polarized. Conversely, in proportional electoral systems, the more proportional nature of competition incentivizes large parties to focus on the issues that voters associate them with. Thus, these parties champion for more issues, but do not address each issue as in depth as those in majoritarian systems. Consequently, the level of polarization between parties is lower. This theoretical finding has implications on cross-country differences in negative campaigning and polarization in the legislature.