Predetermined Prices and the Allocation of Social Risks
提出一种瓦尔拉斯解释，说明固定价格（价格或交易量不反映所有公开信息）为何存在。这种刚性价格体系有助于分担社会风险，但可能导致配置扭曲，使保险均衡价格高于精算公平水平。非或有债权市场仅在保险“收益”超过配置扭曲“成本”时才活跃。固定价格均衡是受约束的最优，不能被适当约束的中央计划者支配。
We propose a Walrasian explanation for the existence of fixed prices, i.e., of trades in which either the price or the quantity exchanged does not reflect all publicly available information. Such trades result in a rigid price system that facilitates the sharing of social risks; they may also cause allocative distortions that increase the equilibrium price of insurance above its actuarially fair level. We demonstrate that the market for noncontingent claims is active only when this insurance "gain" outweighs the "cost" of allocative distortions. Fixed price equilibria are constrained optima, i.e., they cannot be dominated by an appropriately constrained central planner.