σ-Optimality and Fairness
证明σ最优性（Campbell 1988年提出的概念）是帕累托最优与无嫉妒之间一致性的充分条件，并利用可微性方法给出了Campbell关于σ最优性与价格均衡等价定理的简单证明。
Consistency between Pareto optimality and no envy requires some assumptions on the structure of the set of Pareto optimal allocations. Here the author proves that sigma-optimality--a concept first introduced by D. Campbell in his 1988 paper--is a sufficient condition. Campbell proved the equivalence between between sigma-optimality and price equilibrium. Using a differentiability approach, the author also gives a simple proof of that result. Copyright 1994 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.