Objective/context:

This article presents a comparative analysis of the system of simultaneous and open presidential primaries (PAS, for its acronym in Spanish) in Latin American countries that have adopted legislation on the subject. In what appears to be a growing trend, nine countries-with differences among them-have established a PAS regime regulated by the electoral body and with public financing.

Methodology:

First, a description is presented to characterize and classify different PAS systems, considering their main normative differences. Then, hypotheses about their possible effects are proposed based on the literature on presidential primaries and electoral systems. Finally, taking into account the results of the primaries carried out and the subsequent presidential elections, an attempt is made to show to what extent the PAS system encourages citizen participation and competition for nomination, whether it favors or harms the parties that carry them out, and its capacity to stabilize the party system.

Conclusions:

Factors that stimulate participation, such as compulsory voting and simultaneity with other elections, and encourage competition, such as open presidential ticket, are identified. No institutional factors are found to directly benefit or harm the groups that decide the candidacy in a primary, although conflicting primaries seem to harm them. The ability of the PAS system to stabilize party systems seems to depend on its interaction with other institutional and political factors.

Originality:

This is the first work that ventures into a comparative analysis of the PAS system with regional coverage.