Choosing how to choose presidents: Parties, military rulers, and presidential elections in Latin America

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.