Corporate boards, experts panels, parliaments, cabinets, and even nations all take important decisions as a group. Selecting an efficient decision rule to aggregate individual opinions is paramount to the decision quality of these groups. In our experiment we measure revealed preferences over and efficiency of several important decision rules. Our results show that: (1) the efficiency of the theoretically optimal rule is not as robust as simple majority voting, and efficiency rankings in the lab can differ from theory; (2) participation constraints often hinder implementation of more efficient mechanisms; (3) these constraints are relaxed if the less efficient mechanism is risky; (4) participation preferences appear to be driven by realized rather than theoretic payoffs of the decision rules. These findings highlight the difficulty of relying on theory alone to predict what mechanism is better and acceptable to the participants in practice.

公司董事会、专家小组、议会、内阁，甚至国家都作为一个整体做出重要决策。选择有效的决策规则来汇总个人意见对于这些群体的决策质量至关重要。在我们的实验中，我们测量了几个重要决策规则的显性偏好和效率。我们的结果表明：（1）理论上最优规则的效率不如简单多数投票那么稳健，实验室中的效率排名可能与理论存在差异；(2) 参与限制往往阻碍更有效机制的实施；(3) 如果效率较低的机制有风险，这些限制就会放宽；(4) 参与偏好似乎是由决策规则的实际收益而非理论收益驱动的。