Electoral Reform, Party Bias, and Coalition Incentives in Chile's Congress

• In Event: Electoral Systems as a Source of Bias

Abstract

This paper examines the consequences of electoral reform for political parties and constituent representation in Chile’s Congress. The analysis focuses on the bias inherent in the rules, the implications of vote concentration within districts, and the incentives for coalition formation. We argue that prior to the 2015 reform, the largest bias favored the strongest party in the list coming second in the district, whereas after the reform the largest bias favors junior partners within lists. Contrary to the prediction that the reform would eliminate incentives for coalition formation, we show that such motivations are also present under the new rule. However, we also show that the 2015 reform ended up promoting greater fragmentation in Congress, as some of its critics predicted. The paper expands our understanding of open list proportional representation and how incentives for representation and party bias change as district magnitude increases.

Authors

• Eduardo Aleman, University of Houston

• Ernesto F. Calvo, University of Maryland

• Jose M. Cabezas, Universidad Mayor