Frédéric Malherbe

We study the information aggregation properties of unanimous voting rules in the laboratory. In line with theoretical predictions, we find that majority rule with veto power dominates unanimity rule. We also find that the strategic voting model is a fairly good predictor of observed subject behavior. There are, however, cases where organizing the data seems to require a mix of strategic and sincere voting. This pattern of behavior would imply that the way majority rule with veto power is framed may significantly affect the outcome of the vote. Our data strongly supports such an hypothesis.

Published: Bouton, Laurent & Llorente-Saguer, Aniol & Malherbe, Frédéric, 2017. "Unanimous rules in the laboratory," Games and Economic Behavior, Elsevier, vol. 102(C), pages 179-198. citation courtesy of

A group of agents wants to reform the status quo if and only if this is Pareto improving. Agents have private information and may have common or private objectives, which creates a tension between information aggregation and minority protection. We analyze a simple voting system - majority rule with veto power (Veto) - that essentially resolves this tension, for it combines the advantageous properties of both majority and unanimity rules. We argue that our results shed new light on the evolution of voting rules in the EU institutions and could help to inform debates about policy reforms in cases such as juries in the US.

Published: Laurent Bouton & Aniol Llorente-Saguer & Frédéric Malherbe, 2018. "Get Rid of Unanimity Rule: The Superiority of Majority Rules with Veto Power," Journal of Political Economy, vol 126(1), pages 107-149.