The psychological partisan effect of electoral systems: How ideology correlates with strategic voting

Abstract

Districted proportional systems give an edge to right-wing parties that are more popular in rural areas where district magnitude is small and large parties are mechanically advantaged. In this paper, we explore the role played by voters in this bias by looking at how ideology correlates with strategic voting. We analyze survey data from 44 elections in Western Europe and find that left-wing voters are more likely to support a party that is not viable (p < 0.01), but once in this position they seem less likely to desert this party for one that is viable (p < 0.1). Further, we find that this pattern is likely driven by the intensity of partisan preferences as left-wing voters are on average more attached to their favorite party and thus more reluctant to desert it (p < 0.01). Our study thus demonstrates that the psychological effect of districted proportional systems amplifies the mechanical one in advanced industrial democracies.