【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.

要旨：I develop a monopolistic competition model with pollution to analyze the effects of environmental policy on the average productivity of a country. In the model, firms are heterogeneous in their productivity. Given a particular distribution function of technology, I show that a stricter environmental policy will increase average productivity, and will have positive effects on the marginal decrease of profits and environmental damage. In addition, I show the optimal tax rate in a closed economy. In an open economy model, the environmental policy of a country will affect the average productivity of a trading partner. In other words, a stricter environmental policy in a home country leads a decrease in the productivity of a foreign country.