要旨：In this paper, we focus on the impacts of trade on workers' skill formation and wage structure in the presence of heterogeneous workers. As unskilled, workers are identical in their productivity. If workers train himself / herself, he/she becomes a skilled worker. We assume that workers are heterogeneous in their training costs. With above settings, we show that trade openness enhances skill formation and raises the real wage disparity between skilled and unskilled workers though it makes welfare of all agents better off. In addition, trade openness leads to rises in income inequality in some parameter ranges. Finally, we show that compared to export, FDI enhances skill formation, when the fixed costs for FDI is small, or the number of trade partner countries is large, or transport costs of manufactured goods are high.

要旨：We analyze wholesale pricing and retail pricing when a monopolistic manufacturer sells its product to conventional retailer and electronic retailer. As a result we show wholesale price discrimination between conventional retailer and electronic retailer. This reason is that a monopolistic manufacturer wants retailers to compete heavily in the retail market and a monopolistic manufacturer charges higher wholesale price to the retailer having an advantage in the retail market. This behavior of a monopolistic manufacturer distorts a fair retailers' competition and we also show that social welfare is improved at most cases if the government regulates wholesale price discrimination.

要旨：In this paper, we examine the existence of agglomeration economies on production in the Japanese manufacturing industry using plant-level 4-digit SIC data and new agglomeration and co-agglomeration indices for 1985, 90, 95, and 2000. This agglomeration and co-agglomeration indices are calculated in Tokunaga and Akune (2004, 2005), and Tokunaga, Kageyama, and Akune (2005), based on Ellison and Glaeser (1997). Using a flexible translog production function and cost share equation as suggested by Kim (1992), we found that positive agglomeration economies on production in the Japanese manufacturing industry exist in absence of any restriction on homotheticity.

要旨：As the rapid development of broadband Internet access services continues, particularly fiber to the home (FTTH) services, the digital divide between provincial and urban areas is becoming a big social issue in Japan. We classify the issue into two problems: access to high-speed Internet and service utilization of high-speed Internet access. This paper focuses on the latter problem by quantitatively and qualitatively investigating whether a digital divide problem exists based on Internet service utilization. Consequently, we discover that willingness to pay (WTP) for public services over FTTH is almost identical between provincial and urban areas. Furthermore, territorial digital broadcasting over FTTH accounts for a large part of WTP in provincial areas, while tele-working and tele-education are also important as public services over FTTH in urban areas.

要旨：This paper considers a class of migration dynamics with forward-looking mobile workers in a many-region solvable variant of the core-periphery model of Krugman (Journal of Political Economy 99 (1991)). We find that our static model admits a potential function, which allows us to identify a location distribution of workers that is uniquely absorbing and globally accessible under the perfect foresight dynamics whenever the degree of friction in location revisions is sufficiently small. In particular, when trade barriers are low enough, full agglomeration in the region with the highest barrier is the unique stable distribution for small frictions. New aspects in trade and tax policy that arise due to forward-looking behavior are discussed.

要旨：各都市内の空間構造を陽表的に取り入れた多都市動学モデルを提案、分析。建物の耐久性を考慮しつつ、地域（国）の人口・経済成長に応じて各都市がどのように開発されるかを示した上で、後の時点においてどの地点から衰退がはじまるかを考察（通常の条件下では、古い都市の中心部または都市境界付近。）建物の歴史的価値・完全予見・再開発・人口移動を含む場合に関して、それぞれ拡張を行う。歴史的価値に関する実証分析も行い、結果を提示。

要旨：The aim of this paper is to qualify the claim that regulating a competitive transport sector is always detrimental to consumers. We show indeed that, although transport deregulation is beneficial to consumers as long as the location of economic activity is fixed, this is no longer true when, in the long run, firms and workers are freely mobile. The reason is that the static gains due to less monopoly power in the transport sector may well map into dynamic dead-weight losses because deregulation of the transport sector leads to more inefficient agglomeration. This latter change may, quite surprisingly, increase consumer prices in some regions, despite a more competitive transport sector. Transport deregulation is shown to map into aggregate consumer welfare losses and more inequality among consumers in the long run.