Electoral Volatility and Party System Polarization in Latin America, 1992–2018

Democracy in Latin America is under extraordinary strain due to rising polarization over the past decades. Existing studies suggest that electoral volatility influences party system polarization by incentivizing parties to adopt polarizing strategies as a means of survival. However, I identify several drawbacks in this research and subject these findings to a more specific empirical test, focusing on 18 Latin American countries from 1992 to 2018. My results partly diverge from previous studies, suggesting that a growing vote share for new parties drives polarization but not the total level of volatility. Having extended the theoretical framework, it follows that newcomers will either locate at the fringes of the political spectrum or cause existing parties to differentiate themselves by moving to extremes. This also reflects the persistent struggle for party systems in the region to institutionalize.