要旨：We present a general equilibrium two-country model of Cournot oligopoly with free entry. Two countries are asymmetric and separated by distance. Individuals remain unskilled in the traditional sector or acquire skills to work in oligopolistic industry. A larger country has a greater share of skilled labor, pays higher wages and a proportionately greater number of oligopolistic firms than a smaller country. Reductions in trade costs induce skill acquisition and improve welfare for everyone but the benefits are greater for a smaller country.

要旨：We construct a two-region model of monopolistic competition with mobile entrepreneurs. Typical implicit assumption on increasing returns to scale sector is that firms can produce and sale only at one place. We explicitly introduce multi-plant case and examine location equilibrium with decreasing transpiration costs. The difference between single-plant and multi-plant firms lies in export fixed cost and set-up fixed cost of multi-plant. We find that at certain transportation costs entrepreneurs change their organization type from multi-plant to single-plant and, with further decrease in transportation costs, firms concentrate in one region.

【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.

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.

要旨：Investigations of the effect of quality differences on heterogeneous performance in exporting have been limited by lack of direct measures of quality. We examine exports of French wine, matching the exporting firms to producer ratings from two wine guides. We show that high quality producers export to more markets, charge higher prices, and sell more in each market. Exports of champagne exhibit a pattern of quality sorting predicted in our model. More attractive markets are served by exporters that, on average, make lower rated champagne. Market attractiveness has a weakly negative effect on prices and a strongly positive effect on quantities, confirming the sign predictions of a simple quality sorting model.

要旨：We consider a vertically integrated rail service provider, a congested, capacity limited network, and two customers. One customer demands short- and one long-distance services. The supply is determined by a regulator choosing capacity limits, service charges, and allocation regimes. Regimes can be of two types: (i) a priority rule ‘revenue maximization’ and (ii) a scarcity premium. Our key results are based on a Monte Carlo simulation. We find that no regime dominates the other one in all respects. In particular, if total surplus is relevant and service charges are low or consumer surplus is relevant, revenue maximization should be preferred.