“Kick Them Out” as a Voting Strategy: Theory and Evidence from Multimember District Elections

To understand how electoral systems shape representation, we need to identify whether voters react to strategic incentives or naïvely use suboptimal heuristics irrespective of electoral systems. To this end, we utilize the difference in optimal voting across single-member and multimember districts. In single-member districts, semi-sincere voting (i.e., voting for the most-preferred party/candidate among the viable ones) is optimal and observed widely; however, this strategy is suboptimal in multimember districts. We formalize that voters should instead vote to kick out their least preferred party/candidate. We empirically analyze individual-level data of preferences and vote choices in diverse contexts, including a laboratory experiment in the United Kingdom and a closed-list proportional representation election in Romania. Observed voters’ behaviors are concordant with the hypotheses derived from the theoretical model, suggesting that voters sensitively change their strategies in response to the strategic incentives provided by electoral systems.