要旨：競合する２鉄道路線の最適な快速列車停車駅の選択と、社会的厚生に与える影響についての分析

要旨：This paper explores the interplay between commodities' transportation costs and workers' commuting costs within a general equilibrium framework a la Dixit-Stiglitz. Workers are mobile and choose both a region where to live as well as an intraurban location. Contrary to general beliefs, we show that a more integrated economy need not be more agglomerated. Instead, we show that low transportation costs lead to the dispersion of economic activities. This is because firms and workers are able to alleviate the burden of urban costs by being dispersed, while retaining a good access to all varieties.

要旨：本研究では親が子に教育を施し、それにより子の所得が影響を受けるOLGモデルを、集積の経済を考慮した人口移動が常時自由な２地域モデルの枠組みで分析する。本研究の特色は、①初期状態として能力水準の等しい個人を与えても、世代交代を通して地域間で教育水準に格差のある長期均衡に到達しうる。②長期均衡において人口移動に対しロックインが働くが、とりわけ１方向の人口移動に対してのみロックインが働く、「片側ロックイン」の概念に触れ、地方が一方的な人口流出の危機にさらされる可能性を指摘する。

要旨：We analyze how the interplay between urban costs, wage wedges and trade costs may affect the inter-regional location of firms as well as the intra-urban location, within the central business district or in a secondary employment centre (SEC) of the selected region. In this way we investigate, on the one hand, how trade may affect the internal structure of cities and, on the other hand, how decentralizing the production and consumption of goods to subcentres changes the intensity of trade by allowing large metropolitan areas to maintain their predominance. We show that, despite low commuting costs SECs may emerge when the urban population is large and communication technologies are efficient, two features that seem to characterize modern economies. Moreover, when trade costs fall from high levels, the economy moves gradually from dispersion to agglomeration, favouring the formation of SECs. In an integrating world, however, the centre of a small monocentric city could be more attractive than subcentres of large polycentric cities. Nevertheless, the core retains its predominance through the relative growth of its main centre, which occurs at the expense of its subcentres.

要旨：We analyze the location decisions where three firms locate sequentially under uncertainty about consumers’ preference with spatial competition. Contrary to the results of previous studies under uncertainty about consumers’ preference, we can show that there exists equilibrium where the second firm imitates the location of the first firm, considering that firms could learn the information about consumers’ preference. Because consumers’ preference is clarified by the differentiation of locations, the second firm locates the same location as the first firm in order not to clarifying consumers’ preference.

要旨：I analyze the effects of competition on R&D effort (in a non-tournament context) and obtain robust results that hold for a variety of market structures, including markets with and without barriers to entry and markets characterized by either price or quantity competition. The approach encompasses models of direct investment to reduce costs as well as models where cost reduction arises because the agency problem between managers and owners in an asymmetric information context (X-inefficiency) is better resolved. It is found that increasing the number of firms tends to reduce R&D effort, whereas increasing the degree of product substitutability, with or without free entry, increases R&D effort―provided that the total market for varieties does not shrink. Increasing the total market size increases R&D effort.

要旨：This paper incorporates urban congestion costs in the production of manufactured good into Krugman's model (1991) in order to examine the impact of land costs on the choice of firm's locations and its effect on industrial agglomeration. Compared to a conventional monopolistic model with a core-periphery framework, we show that the equilibrium region configuration is dependent on the effects of the transportation cost as well as the land cost. We highlight the land cost effect in the firm's production and find that asymmetric equilibria may arise, in which manufacturing is unevenly distributed between regions, when transport costs are relatively low. However, when the transport costs increase and are large enough, the land cost effect is insignificant and the outcome will converge to Krugman's results (i.e., either full agglomeration or complete dispersion). This finding may feature that the emergence of small industrial centers usually accompanied by large ones in the real world.

要旨：We investigate where cities are located in a spatial economy and why they tend to get 'locked-in' at particular sites. Building on Fujita and Krugman (1995) we show that geography, or transportation technologies, or both, must exhibit some 'non-smoothness' for cities to possibility become 'locked-in' in location space. A direct consequence generically sustained when both space and transportation technologies are smooth, whereas it can in the presence of transportation hubs and / or non-smooth transport cost functions. Our results suggest that the cities are drawn to transportation hubs during the early stages of economic development, whereas they could be sustained in many other locations during later stages. This suggests that history crucially matters, yet also shows that there is less room for historical accidents in explaining the location of cities than usually put forward in the literature.

要旨：The existing literature on regional convergence has centered round the empirical relationship between initial per capita income and its long run growth rate found among the regions in the developed countries. The fundamental basis of the 'converging' outcome is the neo-classical assumption of the law of diminishing returns to capital. In contrast to the conventional results of the developed countries, the present paper has found that Indian states have been diverging during the post independent period. This is being tested in terms of both β-convergence and σ-convergence. By pursuing our analysis with a systemic data set available for 1970-96 we identify different explanatory variables which determine the pattern of interregional growth in India. In spite of active policy of the Central Government to remove interregional imbalance, private investment and discretionary public expenditure have contributed towards interregional divergence in per capita income.

要旨：In this paper, urban land development problem is considered, that is, whether the landowner should construct a building at present for sale in the future with considering the uncertainty of building price. Uncertainty of building price is characterized by possibility distribution to reflect the potential how much the building price will be in the future, which is a kind of likelihood to show similarity between the predicted future situation and the samples appeared in the past time. Two focus points, called active focus point and passive focus point are introduced for balancing satisfaction and plausibility to show which values should be considered for making decision with possibilistic information. Different types of investors, such active one, passive one and more easily satisfied one are considered. The proposed model provides novel insights into individual investment behavior of urban land development in the real world and also some useful regulatory policy for urban land development.