Sufficient Conditions for Inessentiality
给出纯交换序列经济中均衡非本质性的三个充分条件，涉及异质先验、状态依赖效用和非对称信息，为市场完全性概念提供新解释，并揭示投机条件与价格依赖交易的作用。
Three theorems state conditions sufficient for the inessentiality of equilibrium in a pure exchange, sequence economy. The agents have uncommon priors, state-contingent utility functions, and asymmetric information in every trading period, and they trade different sets of event-contingent claims in different periods. The theorems provide alternative interpretations of the concept of market completeness, reveal two fundamentally different ways to obtain inessentiality, and shed light on the conditions permitting speculation and the role of price-contingent trading. None of the theorems requires ex ante Pareto optimality or the absence of arbitrage opportunities. Copyright 1993 by The Econometric Society.