Econ Papers Daily / 期刊论文
Maskin无理性条件下的两人不可能性
Maskin’s two-person impossibility without rationality
摘要
With two individuals and unrestricted rational preferences, Nash implementation of Pareto efficiency forces dictatorship (Hurwicz and Schmeidler, 1978; Maskin, 1999). We show that this conclusion needs very little rationality. On any domain containing two families of states—blocking and polarization—a behaviorally efficient social choice rule is Nash implementable if and only if it equals, at every state, one fixed individual’s choice from the grand menu. The rational domain recovers the classical theorem, while all WARP-violating choice profiles qualify with at least four alternatives. Two-person implementation of efficiency is dictatorial with this much rationality, and it needs no more.
中文摘要
在两个个体且理性偏好不受限制的条件下，帕累托效率的纳什实施必然导致独裁（Hurwicz and Schmeidler, 1978; Maskin, 1999）。我们表明，这一结论所需理性程度极低。在任何包含两类状态——阻塞与极化——的域上，一个行为有效的社会选择规则是纳什可实施的，当且仅当它在每个状态上都等于某一固定个体从大菜单中的选择。理性域可还原经典定理，而所有违反WARP的选择剖面在至少四个备选方案下均满足条件。两人效率实施在如此理性程度下是独裁的，且无需更多理性。