Electoral systems determine the role that representatives’ party affiliations play in political representation. According to conventional expectations, party affiliation drives the behavior of representatives when they are elected under a proportional system, while majoritarian systems mute the role of party affiliation by forcing politicians to converge to the median position of their constituency. This study directly tests these predictions within a common party system by matching referenda decisions of constituents with voting behavior of their representatives who are elected either under a majoritarian or proportional system.
