Presidential Election Laws and Multipartism in Latin America

This article examines the interaction between the rules governing presidential elections and multipartism in Latin America. Data from 16 Latin American systems are examined through the use of a multivariate model to gain an understanding of the independent impact of presidential electoral formula (plurality vs. majority), the timing of presidential and legislative elections (concurrent vs. nonconcurrent) and legislative district magnitude on legislative multipartism, and by extension, on the number of relevant political parties operating in the nation. The findings demonstrate the strong and significant impact which formula and timing have on multipartism. They also point to the importance of examining the interaction between elections for different constituent institutions. Finally, they underscore the applicability of Duverger's law to presidential elections.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68710/2/10.1177_106591299404700103.pd