School of Economics and Finance

No. 778: Multicandidate Elections: Aggregate Uncertainty in the Laboratory

Laurent Bouton , Georgetown University, Université Libre de Bruxelles, CEPR and NBER
Micael Castanheira , Université Libre de Bruxelles, FNRS and CEPR
Aniol Llorente-Saguer , Queen Mary University of London

December 20, 2015

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The rational-voter model is often criticized on the grounds that two of its central predictions (the paradox of voting and Duverger's Law) are at odds with reality. Recent theoretical advances suggest that these empirically unsound predictions might be an artifact of an (arguably unrealistic) assumption: the absence of aggregate uncertainty about the distribution of preferences in the electorate. In this paper, we propose direct empirical evidence of the effect of aggregate uncertainty in multicandidate elections. Adopting a theory-based experimental approach, we explore whether aggregate uncertainty indeed favors the emergence of non-Duverger's law equilibria in plurality elections. Our experimental results support the main theoretical predictions: sincere voting is a predominant strategy under aggregate uncertainty, whereas without aggregate uncertainty, voters massively coordinate their votes behind one candidate, who wins almost surely.

J.E.L classification codes: C92, D70

Keywords:Rational voter model, Multicandidate elections, Plurality, Aggregate