An experimental study of the efficiency of unanimity rule and majority rule

Scholars traditionally claim that unanimity rule is more capable of producing Pareto optimal outcomes than majority rule. Dougherty and Edward (Public Choice 151(3):655–678, 2012) make the opposite claim assuming proposals are either random, sincere, or strategic. We test these competing hypotheses in a two-dimensional framework using laboratory experiments. Our primary results suggest: (1) majority rule enters the Pareto set more quickly than unanimity rule, (2) majority rule leaves the Pareto set at the same rate as unanimity rule, and (3) majority rule is more likely to select a Pareto optimal outcome than unanimity rule at the end of the game.