Turnout in referendums: A formal model with observations from Colombia

• In Event: Comparative Latin American Politics: Short-term Dynamics and Long-term Processes

Abstract

Why is turnout so much lower, on average, in referendums than in candidate elections? We construct a formal model of mobilization in elections and show that, in candidate elections, the natural alignment of incentives between party leaders and candidates is conducive to effective mobilization. In referendums internal party structures are crucial for mobilization efforts given the absence of electoral incentives. Centralized parties, defined by greater cohesion and control, are better able to mobilize their operatives. In contrast, mobilization by decentralized parties depends largely on the efforts of individual politicians and leaders rather than national-level party positions. We argue that more variable effort in the latter case results in lower turnout among supporters than in the former. We test the model with qualitative and quantitative data from the 2016 Colombian referendum on a peace agreement. We find cross-party differences in mobilization effort that are consistent with the model's predictions.

Authors

• Radha Sarkar, Yale University

• Susan C. Stokes, University of Chicago

• Eli Gavin Rau, Yale University