Primaries Through the Looking Glass: The Electoral Effects of Opening the Selection of Top Candidates

This article revisits the foundations of prior research on the effects of plebiscitarian selection mechanisms on candidates' electoral strength. While previous studies do not nest political parties' decision making, the authors argue that party primary effects entail the interdependence of party procedures for candidate selection. The article assesses the validity of the two approaches. Using original data from seven parties and 296 regional elections in Canada, Germany and Spain, and from sixty-two pre-election polls in Germany and Spain, it shows that, other things equal, primary-selected candidates are not stronger than those selected by other procedures. However, there is evidence of a penalty for parties that do not select candidates by primary when their main rival does, in particular when the primary election is not divisive and is held closer to the general election.