This paper examines electoral volatility in Latin America from 1932 to 2018, covering both presidential and lower chamber elections. The paper makes two contributions. First, we present a new, carefully documented dataset about electoral volatility and the vote share of new parties. Scholars interested in both subjects will be able to use the data to explore a wide range of issues. We contribute to the descriptive knowledge about patterns of electoral volatility and the vote share of new parties in Latin America. Second, we contribute to theoretical knowledge about extra-system volatility (the part that results from the emergence of new competitors) and within-system volatility (the part of volatility that stems from aggregate vote transfers among established parties) and to incipient debates about theoretical expectations about differences between extra- and within-system volatility. Poor economic growth, a perception of pervasive corruption, and low levels of partisanship are fertile terrain for new parties (extra-system volatility). Party system polarization and a fragmented party system foster within-system volatility.

本文考察了 1932 年至 2018 年拉丁美洲的选举波动，涵盖总统和下议院选举。这篇论文有两个贡献。首先，我们提出了一个新的、经过仔细记录的关于选举波动性和新政党投票份额的数据集。对这两个学科感兴趣的学者将能够使用这些数据来探索广泛的问题。我们为拉丁美洲选举波动的模式和新政党的投票份额的描述性知识做出了贡献。第二，我们贡献了关于系统外波动性（由新竞争者的出现引起的部分）和系统内波动性（由已建立的政党之间的总投票转移引起的波动性部分）的理论知识，以及关于理论预期的初步辩论系统外波动性和系统内波动性之间的差异。经济增长不佳、腐败普遍存在以及党派偏见低是新政党的沃土（系统外的动荡）。党制两极分化和党制碎片化助长体制内波动。