The party system effects of unstable electoral rules in Latin America

Prior studies have shown that electoral rules fail to determine the number of parties in new democracies due to the uncertainty of voters and politicians about which parties are viable. Latin American democracies, where electoral volatility has generally remained high and party institutionalization low, have been a primary example of this phenomenon. We argue that even in shifting political environments the fragmentation of the party system is likely to become consistent with the permissiveness of electoral rules and the level of social diversity as voters and party leaders accumulate experience with elections and the rate of electoral regime change declines. We find support for these propositions analyzing an original dataset on Latin American democratic elections. This article contributes to research on electoral systems and political parties by identifying the conditions under which equilibrium electoral outcomes can be expected after a transition to democracy in unstable institutional settings.