Abstract

Students of presidential regimes claim that while the combination of plurality rule for presidential elections and concurrent electoral cycles favors bipartism, majority rule for electing presidents favors multipartism. I argue that a reverse causality also affects the relationship between party systems and electoral systems. Using a bargaining model of institutional change, I propose that while dominant and large parties are likely to choose plurality rule and concurrent elections, small parties are likely to choose majority rule. I also argue that military rulers and military-civilian coalitions tend to follow the logic of electoral choice of small parties. These hypotheses are supported by a statistical analysis of the determinants of electoral choice in 49 cases of constitutional change in Latin America. Mechanisms of choice are analyzed in several episodes of electoral reform, including a negative case that suggests explanations of electoral choice not covered by the model presented in this paper.