According to conventional wisdom, closed-list proportional representation (CLPR) electoral systems create incentives for legislators to favor the party line over their voters’ positions. However, electoral incentives may induce party leaders to tolerate “shirking” by some legislators, even under CLPR. This study argues that in considering whose deviations from the party line should be tolerated, party leaders exploit differences in voters’ relative electoral influence resulting from malapportionment. We expect defections in roll call votes to be more likely among legislators elected from overrepresented districts than among those from other districts. We empirically test this claim using data on Argentine legislators’ voting records and a unique dataset of estimates of voters’ and legislators’ placements in a common ideological space. Our findings suggest that even under electoral rules known for promoting unified parties, we should expect strategic defections to please voters, which can be advantageous for the party’s electoral fortunes.

中文翻译：

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封闭式比例代表制下的选区效应和立法异议

根据传统观点，封闭式比例代表制 (CLPR) 选举制度会激励立法者支持政党路线而不是选民立场。然而，选举激励措施可能会诱使党的领导人容忍一些立法者的“推卸责任”，即使在 CLPR 下也是如此。本研究认为，在考虑应该容忍哪些人偏离党的路线时，党的领导人利用了因分配不当而导致的选民相对选举影响力的差异。我们预计，从代表人数过多的地区选出的立法者比其他地区的立法者更有可能出现唱名投票的叛逃。我们使用阿根廷立法者的投票记录数据和一个独特的估计选民和立法者在共同意识形态空间中的位置的数据集对这一主张进行了实证检验。