【応用ミクロ経済学ワークショップと共催】 要旨：Armington Assumption in the context of multi-regional CGE models is commonly interpreted that the same commodity with different origins is an imperfect substitute of each other. A static spatial CGE model that is compatible with this assumption and explicitly considers the transport sector and regional price differentials is formulated. It is shown that the trade coefficients, which are derived endogenously from the optimization behaviors of firms and households, take the form of a potential function. To investigate how the elasticity of substitutions affects the equilibrium solutions, a simpler version of the model, which incorporates 3-regions and 2-sector besides the transport sector, is introduced. It is found that (1) if the commodities produced in different regions are perfect substitutes, the regional economies will either be autarkic or completely symmetric, and (2) if they are imperfect substitutes, the impacts of the elasticity on price equilibrium system as well as trade coefficients are nonlinear and sometimes very sensitive.

【応用ミクロ経済学ワークショップと共催】 要旨：Scotchmer and Wooders (1987) show that efficient clubs are homogeneous when consumers are divisible in Berglas's (1976) anonymous crowding model. However, if consumers are not divisible or if clubs have multiple facilities with economies of scope, mixed clubs are efficient. In such a model, we consider clubs with multiple membership policies for different types of consumers, and show the existence and efficiency of equilibrium with nonlinear policies. We employ entrepreneurial equilibrium, an equilibrium concept with profit-seeking entrepreneurs. In our model, club managers and members of clubs care only about the members' actions, not their types. The equilibrium is efficient in our adverse selection model due to this "anonymity" of crowding effects. Our theorem can be regarded as showing the existence of a core allocation that satis.es envy-free property in the absence of nonanonymous crowding effects.