Replication Data for: 'Kick Them Out' as a Voting Strategy: Theory and Evidence from Multi-member District Elections

To understand how electoral systems shape representation, we need to identify whether voters react to strategic incentives or naively use suboptimal heuristics irrespective of electoral systems. To this end, we utilize the difference in optimal voting across single-member and multi-member 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 multi-member 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 lab 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.

为探究选举制度（electoral systems）如何塑造代议格局，我们需要厘清选民究竟会响应策略性激励，还是会不顾选举制度约束，天真地采用次优启发式决策策略。为此，我们利用单席位选区（single-member districts）与多名选区（multi-member districts）间最优投票策略的差异开展研究。在单席位选区中，半真诚投票（semi-sincere voting）——即从具有胜出可能性的选项中投票给最偏好的政党/候选人——是最优策略，且该行为在现实中广泛存在；但这一策略在多名选区中属于次优选择。我们通过形式化分析指出，选民此时应转而采取投票以淘汰自身最不偏好的政党/候选人的策略。我们针对多场景下的个体层面偏好与投票选择数据开展实证分析，涵盖英国的实验室实验以及罗马尼亚的封闭名单比例代表制（closed-list proportional representation）选举案例。观测到的选民行为与理论模型推导的假说相符，这表明选民会敏锐地根据选举制度提供的策略性激励调整自身投票策略。