title: Multicandidate Elections: Aggregate Uncertainty in the Laboratory.
abstract: The rational-voter model is often criticized on the grounds that two of its central predictions (theparadox of votingandDuverger'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 ofaggregate uncertaintyabout 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.
authors.affiliation: Georgetown University, Université Libre de Bruxelles (ECARES, SBS-EM), CEPR and NBER.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bouton
authors.affiliation: Université Libre de Bruxelles (ECARES, SBS-EM), FNRS, and CEPR.
authors.forename: Micael
authors.initials: M
authors.lastname: Castanheira
authors.affiliation: Queen Mary University of London.
authors.forename: Aniol
authors.initials: A
authors.lastname: Llorente-Saguer
keywords: Aggregate Uncertainty; Experiments; Multicandidate Elections; Plurality; Rational Voter Model