要旨：We study stability and instability of short-run and long-run equilibria of monopolistic competition with product differentiation. Since monopolistic competition is not either a game of complete information or of incomplete information, dynamic adjustment process of prices should exist in markets given the set of incumbent firms. Moreover, entry and exit of firms occur depending on the levels of individual profits. In the economies under investigation, the total income level of consumers determines whether the differentiated commodities are substitutes or complementarities. We show that there may exist unstable short-run equilibrium and long-run equilibrium. The reason is characterized by decreasing marginal cost and endogenous complementarities between differentiated commodities.

要旨：ハリウッドの映画製作におけるＶＦＸプロジェクトの責任者であるＶＦＸスーパーバイザーの週間コンタクト行動のデータを参加観察により収集し、デジタル・コンテンツ産業集積においてプロジェクトがどのようにコーディネートされているかについてコミュニケーションの側面から分析を行った。

要旨：The purpose of this paper is to discuss the efficient disposal system of industrial waste and the optimal policy to establish it. The economy of our model is composed by four organizations; dischargers, treatment firms, reclaiming firms, and the local governments. To begin with, discharges commission treatment firms to treat them. The treatment firms are imposed the industrial wastes tax by the local governments. The local governments can select either the strict monitoring policy or the subsidy policy for proper treating and can use tax revenues from the industrial waste tax. As the result of our analysis in this paper, we can derive the fact that the recycling rate under the strict monitoring policy is higher that the social optimal rate of recycle of the industrial waste if the local governments choice this policy and use the tax revenues to accomplish it. On the other hand, the social optimal recycling rate of them is established by the subsidy policy for the proper treating when the local governments choice this policy. In our analysis, we can derive some results. One of them is the fact that the recycling rate in the region whose government adopts the subsidy policy for the proper treating is higher than the optimal recycling rate in the region when the interregional transportation cost of industrial wastes is not high relatively. Another results is that it is possible to exist the policy combination of the strict monitoring policies as the equilibrium in spite of social non optimal combination if we take account of the interregional moving of the wastes.

要旨：We propose a simple framework within which taste heterogeneity is a determinant of the scale of production. We show: (i) when taste heterogeneity is small, mass production firms emerge; (ii) when taste heterogeneity is large, small-scale production firms emerge; and (iii) when the degree of taste heterogeneity is intermediate, the symmetric equilibrium is unstable, and mass production firms and small-scale production firms coexist. Furthermore, we extend it to a geographic framework and obtain a historical evolution of American marketing that is characterized by three phases: a geographically fragmented market with small-scale production; a geographically unified market with mass production; and a geographically unified but characteristically segmented market.

要旨：Cremer et al.(1997、Journal of Public Economics)のAll or nothingの公共財供給モデルを紹介し、これまでの拡張研究を通じて、同モデルの有効性を示す。

要旨：この論文は、近年日本において提案された都市雇用圏（金本・徳岡、2002）をベースに、都市規模に関する経済理論及び各種社会経済の統計データを応用して最適都市規模を実証したものである。その結果、2000年の都市雇用圏の最適規模は約1,800万人と推計された。そして、この最適都市規模の観点により、3,200万人を有する東京圏は明らかに過大であり、1,200万人の大阪圏や500万人の名古屋圏は過小であると結論付けた。

要旨：In this paper, we develop a two-country four-region model allowing for a core periphery pattern inside countries. We then examine how both the integration and the agglomeration process inside a given country affects the pattern of specialization and international trade. We also analyze how agglomeration processes interact from one country to the other and in particular how agglomeration forces in one country is affected by the spatial distribution of activity in the partner country. The main results of the analysis are the following: (i) agglomeration proves to be a source of comparative advantages in the industries featuring economies of scale on condition that this agglomeration process is driven by market forces; (ii) both integration and agglomeration in one country reduces the likelihood to observe agglomeration in the partner country.

要旨：地域の統合度や労働移動制約環境の異なる３つの経済圏、アジア、ヨーロッパ、中国を取り上げ、製造業の雇用者数によるLocational Gini Indicesを計測し、産業立地がアジアでは概ね拡散の傾向を、ヨーロッパや中国では集積の傾向を示していることを認めた。相対雇用者構成比の変化率のパネル分析から、アジアでは賃金がその拡散力‘Centrifugal force’として、ヨーロッパでは市場アクセスが、中国では賃金がその集積力‘Centripetal force’として、各経済圏の特性に応じNEGの理論モデルが示唆する方向に働いていることが検証された。また比較優位はアジアでは産業集積に一定の説明力を残している結果を示した。

要旨：本論文では、地震に関する地域危険度が、どの程度地価や賃貸住宅の家賃に影響を与えているのかを、東京都の例で分析する．方法としてヘドニック・アプローチに基づく実証分析を行い、その実証結果の簡単な危険回避行動モデルによる理論的な妥当性の評価、新耐震基準に基づいた耐震化投資は家主にとって収益的な投資であるかについての簡単な費用便益分析を行なっている。