Coping with complexity: ballot position effects in the Finnish open-list proportional representation system
Peter Söderlund, Åsa von Schoultz, Achillefs Papageorgiou
Numerous studies show that candidates listed first on the ballot win more votes than candidates listed further down the ballot. Also candidates listed near or at the end of the ballot may have an advantage over those listed in the middle. We advance our understanding of ballot position effects by demonstrating how the ballot position effect grows stronger with the complexity of the electoral environment. This study of candidates' intra-party vote shares in six six parliamentary elections in Finland, which has open-list proportional representation system with mandatory preference voting for candidates, shows that candidates listed early and late on the ballot win more preference votes. This applies for both alphabetical and rank-ordered lists. Further, the ballot position effect is moderated by the complexity of the electoral environment. The longer the list of candidates, and the fewer the number of incumbents on the list, the greater the ballot position effect is.