Informed Speculation with Imperfect Competition
用需求函数纳什均衡分析非竞争理性预期模型，发现交易者考虑自身需求对价格的影响，避免了竞争模型中的“精神分裂”问题；价格揭示的信息少于竞争均衡，且在小交易者情形下市场变为垄断竞争，为风险中性交易者获取昂贵私人信息提供了合理模型。
Competitive rational expectations models have the unsatisfactory property, dubbed the "schizophrenia" problem by Hellwig, that each trader takes the equilibrium price as given despite the fact that he influences that price. An examination of information aggregation in a non-competitive rational expectations model using a Nash equilibrium in demand functions shows that the schizophrenia problem is avoided by having each trader take into account the effect his demand has on the equilibrium price. Given a distribution of private information across traders, prices reveal less information than in the competition equilibrium, and prices no longer become fully informative in the limit as noise trading vanishes or as traders become risk neutral. With small traders, the model may become one of monopolistic competition, not perfect competition. In contrast to the competitive model, a reasonable model of endogenous acquisition of costly private information is obtained, even when traders are risk-neutral.