Credibility Versus Competition: The Impact of Party Size on Decisions to Enter Presidential Elections in South America and Europe.

How does a party’s size affect its decision to run a candidate for president? Consistent with the literature, the authors posit that environmental factors influence the likelihood that a party enters the presidential race. However, the authors argue that the effects of these factors are conditional on party size. Large parties are influenced by factors that increase their chances at being competitive, whereas small parties are influenced by factors that allow them to build their credibility. To evaluate the conditional effects of party size, the authors use an original data set of more than 2,400 party-level observations in 23 democracies across South America and Europe from 1975 to 2009. They find that small and large parties respond differently to several environmental conditions, namely, the presence of an incumbent, “crowded” plurality elections, and federalism. The findings have important implications for understanding party strategy and the factors that alter the competition for the most important of political offices. [ABSTRACT FROM AUTHOR]