Electoral contexts that assist voter coordination: Ballot position effects in Poland

•I discuss the problem of voter coordination under open list system.•I investigate the ballot position effects in Polish Sejm elections.•First position on the ballot is associated with higher share of votes.•Proximity to the top of the ballot is associated with higher share of votes.•Incumbency, gender and age also have a significant effect on share of votes.

Hypothetically, in the open list PR system, all contestants, independently of their ballot position, have the same chance of winning a mandate. In practice, candidates placed at the top of the ballot enjoy a large surplus of votes. Their success can be explained by the primacy effect, in which the first ballot position acts as a focal point. The analysis of 6187 candidates running for the Polish Sejm in 2007 finds not only significant gains for top candidates, but that proximity to the upper end of the ballot likewise matters. It correspondingly discovers a weak benefit for candidates placed last on the list. Other sources of candidate advantage such as incumbency, capital city effect, age and gender are also investigated.