Multiplicity of Equilibria and Comparative Statics
利用拓扑指数定理推导出包含生产的经济中均衡唯一性的充要条件，发现唯一性条件过于严格，仅当需求侧像单一消费者或供给侧为投入产出系统时才成立，因此建议重新审视比较静态方法。
Conditions that guarantee the uniqueness of equilibrium in models of economic competition are crucial to applications of these models in exercises of comparative statics. Until now, most of the attention given to the uniqueness question has been focused on pure exchange economies. In this paper we use a topological index theorem to derive necessary and sufficient conditions for the uniqueness of equilibrium in economies with production. Unfortunately, conditions that imply uniqueness appear to be too restrictive to have much applicability. We argue, for example, that the only economically interpretable restrictions that imply uniqueness are either that the demand side of an economy behaves like a single consumer or that the supply side is an input-output system. Our results suggest a need for reformulation of the comparative statics method.