要旨：本稿は高所得者が商品住宅を消費し、低所得者が「経済適用性住宅」を消費する中国の持家制度に基づいて理論モデルを構築する。比較静学分析と政策評価シミュレーション分析によって、中国の持家政策が社会厚生、都市空間構造などに与える影響を評価する。分析の結果、１）高所得者の所得増加は都市境界を拡大させ、2）都市内側境界の地代が上昇すると都市内側地代は上昇し都市境界は縮小し、3）適量の「経済適用性住宅」を供給すると高、低所得者の住宅消費は改善され社会厚生は上昇する。

要旨：Tiebout hypothesis (residential choice depends solely on local public goods) is extensively applied to explain geographic segregation. However, Rhode and Strumpf (2003) find that the Tiebout hypothesis is inconsistent with the long-period empirical data, and therefore a non-Tiebout explanation is needed. This paper provides such an explanation based on the new economic geography framework, into which the heterogeneous preferences of mobile workers on private goods instead of public goods are incorporated. Specifically, two types of mobile workers have different preferences on the products of two industries in the manufacturing sector in a symmetric way. The rigorous general equilibrium analysis conducted here shows that the increasing-returns technology and monopolistic competition form a mechanism endogenously leading to persistent residential segregation. There is an evolving path with decreasing transport costs, in which the two types of mobile workers are segregated, while two industries evolve from dispersion to agglomeration.

要旨：This paper presents a model of economic geography with overlapping generations. Individuals are assumed to decide their location by considering not only where to sell their products when young but also where to buy others’ products when old. The present generation is thus linked to the past generation by a ‘dynamic’ wage equation and to the future generation by an ‘expected’ price index. Such intergenerational linkages induce a strong dispersion force, i.e., without any conventional dispersion force, a symmetric steady state is stable even in the presence of product diversity. Symmetry breaks when the discount factor is sufficiently small. This implies that once intergenerational linkages are taken into account, consumers care about how many varieties are available at which stage of a life cycle. Specifically, the model illustrates the case in which ex ante identical agents in the same generation may be divided into ‘ants’ and ‘grasshoppers’, i.e., those who earn a higher lifetime income and enjoy greater product diversity when old, and those who earn a lower lifetime income and enjoy greater product diversity when young. Finally, the model also suggests a definition of dynamic efficiency of agglomeration and dispersion.

要旨：Openness of economy may or may not accelerate decentralization. We setup a new formal model which captures the essence of the nexus of openness and decentralization where interaction between openness and regional disparity is highlighted. We then empirically examine the effects of openness on decentralization, and especially, validate propositions implied by our theoretical analysis.

要旨：This study explores the antecedents of the spatial variation in market entry rates and extends the density dependence model by relaxing its assumption regarding firm heterogeneity. We argue that market entry is an outcome of new entrants' efforts to resolve competition and uncertainty problems, we theorize and demonstrate interrelatedness between organizational density and market crowding. Using panel data from the Tokyo hotel industry, our analysis not only supports the density dependence model and builds on it by demonstrating that new market entry is more likely to occur when market crowding is low and density is high or density is low and crowding is high.

要旨：This paper investigates the impacts of capital mobility and tax competition in a setting with imperfect matching between firms and workers. The small country always gains and the large country always loses from tax competition, thus implying tax competition leads to redistribution from the large to the small country. However, the large country always attains a higher utility than does the small country. These results imply that our model encapsulates both the "importance of being small" as well as the "importance of being large". We also show that tax harmonization leads to redistribution from the large to the small country.

要旨：This study is intended to examine the effects of environmental policies on employment, the use of polluting goods, and the unemployment rate under a model introducing trans-boundary pollution affecting the productivity of the other productive sectors. That model was designed by Copeland and Taylor [5], transformed into a dualistic economy model, as constructed by Harris and Todaro [10]. Results of our analyses show that reinforcement of environmental policy through control of emissions taxes does not necessarily worsen unemployment in the urban area. Therefore, we show that it is no usually proper to maintain that some environmental pollution can not be avoided to establish economic development.

【ミクロ経済学・ゲーム理論研究会と共催】 要旨：We develop a two-country model of capital tax competition in which firms choose both their location and their number of plants. When firms operate only a single plant, capital is subsidized in equilibrium and firms' profits after subsidy are increasing in subsidies. In the presence of multinational firms capital may, on the contrary, be taxed in equilibrium, provided that being multinational generates sufficient rents. Further, firms' profits after subsidies are decreasing in subsidies due to the pro-competitive effects of more firms 'going multinational'. This pro-competitive effect can give rise to multiple equilibria, one of which may be a 'subsidy trap' characterized by too many multinationals, high subsidies, and low welfare.

要旨：近年、GISで利用可能な空間データはその質量とも、急速に充実しつつある。特に空間現象の時系列的な変化を記述する時空間データについては、様々な種類のものが利用可能になってきている。国勢調査、事業所統計調査、LANDSAT画像など、これまで長く研究に用いられてきたデータに加え、タウンページデータ、IKONOSなどの超高解像度衛星画像データ、レーザーによるトラッキングデータなど、新しいデータ取得技術によって得られる時空間データが現在では比較的容易に入手可能である。しかしながら、このような新たな時空間データを分析するための手法は未だ限定的にしか存在せず、データの有効な利用がなされているとは言い難い。そこでここでは、時空間データの利用可能性とその分析方法について、実例を交えながら広く論ずる。