[UTMD-009] Kick-out Voting: Strategic Voting under the Proportional Representation and Single Non-Transferable Vote Systems(by Hiroto Katsumata, Shunya Noda)


Hiroto Katsumata, Shunya Noda


We analyze kick-out voting, a novel form of strategic voting induced under multi-member electoral systems, such as proportional representation. Our formal theory predicts that voters do not necessarily vote for their most preferred party/candidate who seriously competes for a seat. Instead, voters may vote for the party/candidate who would kick out their least preferred party/candidate, even if it decreases the winning probability of their most preferred. We perform empirical analyses with individual-level data of preferences and vote choices based on three data sets from diverse contexts: (i) A lab experiment in the United Kingdom, (ii) a closed-list proportional representation election in Romania, and (iii) elections under the single nontransferable vote system in Japan. Concordant with our theoretical predictions, we find empirical evidence that voters are attempting to kick out less preferred candidates. Such strategic behaviors may skew vote shares and worsen the quality of representation in these electoral systems.