Uniqueness of Equilibrium in the Classical Capital Asset Pricing Model
证明经典两期均值方差资本资产定价模型的一般均衡不唯一，同一组预期、效用函数和初始财富分布下可能存在多个均衡，资产价格、预期收益率和贝塔值在不同均衡中不同；但任何均衡组合由唯一价格体系支撑，若投资者风险厌恶递减，风险资产均衡配置也由唯一价格体系支撑。
General equilibrium in the classical two-period mean-variance capital asset pricing model is not unique. Corresponding to one single set of expectations, utility functions, and an initial wealth distribution, there may be several equilibria, and an asset may have different prices, expected rates of return, and betas in different equilibria. However, any equilibrium portfolio is sustained by a unique price system, and if investors have decreasing risk aversion, then any equilibrium allocation of the risky assets is sustained by a unique price system.