Open/Closed List and Party Choice: Experimental Evidence from the UK

Articles

Within electoral systems using proportional representation (PR), two types of ballots are commonly used: in closed-list systems, voters choose among parties, and the order in which candidates take seats is fixed within parties; in open-list systems, voters choose among candidates, and the order in which candidates take seats is determined (at least in part) by individual candidate vote totals. By giving voters influence over not just the number of seats each party wins but also which candidates from a given party win seats, open-list systems introduce a measure of intraparty competition among candidates. Political scientists have argued that this intraparty competition tends to reward candidates who have more local background and experience¹and increases the incentive for elected politicians to deliver particularistic service to their voters²and even engage in corrupt activities.³

While the literature helps us understand how different ballot types in PR systems affect legislative behavior, it offers fewer clues about how ballot type affects parties' relative electoral success. This omission is puzzling not just because political scientists have a strong interest in the effects of electoral systems on party systems, but also because the partisan consequences of ballot type should be of first-order importance to the actors most responsible for choosing electoral systems - partisan politicians. Understanding these consequences may thus help us understand how specific features of electoral systems are chosen.

In this article we argue that an important determinant of the effect of ballot type on party support is the level of intraparty disagreement on salient issues. Disagreement among candidates within a party is typically a liability because it suggests disorganization and incoherence, but we offer two reasons why parties that are characterized by such disagreement may do better in open-list elections than in closed-list elections. The first reason is that some voters might find a particular candidate in a diverse party more attractive than the party itself, such that they would vote for that candidate under open lists but would vote for another party under closed lists. The second reason is that some voters may be drawn to the chance to weigh in on intraparty disagreement in open-list elections, such that under open lists they would vote to help one candidate in...