要旨：ファンと呼ばれる消費者が企業間の競争において持つ存在意義を空間競争モデルによって明示的に分析する。近い製品特性をもった製品同士が微妙に差別化された状況で価格競争をしのぎ合いながら、密集した財のバラエティを実現している状況がある。例えば、緑茶飲料などはごくわずかな差異を持った製品が数多く存在する。このような密集した多様性が競争から生み出される要因はファンと呼ばれる消費者にあると考えられる。本研究ではそれらの消費者に焦点を当てて、彼らが市場において果たす役割について分析する。具体的には、ファンの存在をホテリング線分上に明示的に導入した空間競争モデルを考え、企業数2 の2 段階空間競争モデルで、より近い立地で製品特性と価格の競争をランダムにおこなう均衡が得られることを示す。

要旨：This paper establishes the existence and efficiency of equilibrium in a local public goods economy with spatial structures by formalizing Hamilton's (1975 Urban Studies) elaboration of Tiebout's (1956 JPE) tale. We use a well-known equilibrium concept from Rothschild and Stiglitz (1976, QJE) in a market with asymmetric information, and show that Hamilton's zoning policy plays an essential role in proving existence and efficiency of equilibrium. We use an idealized large economy following Ellickson, Grodal, Scotchmer and Zame (1999, Econometrica) and Allouch, Conley and Wooders (2004). Our theorem is directly applicable to the existence and efficiency of a discrete approximation of mono-or multi-centric city equilibrium in urban economics with commuting time costs even if we allow existence of multiple qualities of (collective) residences, when externalities due to traffic congestion are not present.

要旨：This paper argues that currently advanced, aging economies experienced a qualitative change in the role of public education during the process of industrialization. In the early stages of the Industrial Revolution, public education was regarded as a duty that regulated child labor and thereby discouraged childbirth. As these economies developed and the population aged, younger generations came to view public education as a right, whereas older generations desirous of other public services became more politically influential. The eventual policy bias in favor of the elderly placed a heavier education burden on the young, inducing them to have fewer children. This vicious cycle between population aging and the undersupply of public education may have decelerated economic growth in the last few decades.

要旨：Using a model with a fixed cost of regional development, this paper considers how capital tax competition affects transfer and development policies in the presence of regional income disparity. In each country, development policies determine the number of rich (poor) regions that (do not) engage in production activities while transfer policies redistribute income between rich and poor regions. It is shown that the mix of transfer and development policies, as well as the overall expenditure level, is inefficient under tax competition. Since capital tax distortion causes competing governments to overvalue the benefit of regional development, too much tax revenue is spent on development policies and too little on transfer policies. As a result, development policies are used as a means of regional redistribution even if transfer policies are efficient instruments for this purpose.

要旨：We analyze the impact of globalization on individual gains from trade in a general equilibrium model of monopolistic competition featuring income heterogeneity between and within countries. We disentangle two key channels through which trade affects welfare: product diversity and pro-competitive effects. We then show that, although trade always reduces the price-wage ratios in both countries, its impact on variety depends on their relative position in the world income distribution: the choice set in the low income country always expands, while that in the high income country may shrink. When the latter occurs, the richer consumers in the high income country may lose from trade because the relative importance of product diversity versus purchasing power increases with income. To illustrate the quantitative effects, we calibrate the model on the U.S. income distribution and show that U.S. trade with countries of similar GDP per capita makes all agents in both countries better off; whereas trade with larger countries having lower GDP per capita may adversely affect the richest 12-20% of the U.S. population.

【応用ミクロ経済学・産業経済学ワークショップと共催】 要旨：To alleviate congestion and facilitate Asia-Pacific trade the federal and western provincial governments have launched several major transportation infrastructure investments. This paper addresses some public policy issues regarding infrastructure investments of this type. Does the private sector have incentives to make efficient investments and to impose efficient congestion charges? What about local governments? Are subsidies warranted either for investments or for ongoing operations and maintenance of infrastructure? Should governments pursue strategic trade objectives? Do existing institutions, governance structures and regulations facilitate appropriate decisions? Some dangers of making wrong investment decisions are identified.

【応用ミクロ経済学・産業経済学ワークショップと共催】 要旨：We analyze agents' strategic interaction of investment in security and bilateral partnership among them. Each agent confronts with a risk of suffering damage from troubles and disasters such as natural disaster and terrorism. To deal with them, agents have a choice to have investment in pre-disaster phase and partnerships of post-disaster recovery activity. We examine efficient and stable investment in security and partnership network in the game and tension between efficiency and stability. We also compare payoffs of stable networks if multiple networks are stable.

要旨：本研究では、事前・事後割引料金システムの経済厚生を比較する。事前割引料金システムでは、実際の交通サービスの利用に先立って、サービス対価の支払い額が確定している。一方、事後割引料金システムでは、事前に料金メニューのみが提示され、家計のサービス行動に応じて料金が事後的に決定される。このように、事前・事後割引料金システムでは家計と企業のリスク分担構造が異なる。本研究では、以上のリスク分担構造を考慮した３期間モデルを定式化し、事前・事後割引料金システムが企業の利潤、家計の厚生に及ぼす影響を理論的に分析する。その結果、既存の料金システムを併存しつつ、新しく割引料金システムを導入する場合、事後割引料金システムの方が社会的厚生の観点から望ましい結果をもたらすことが明らかになった。

要旨：In an international oligopoly model, this paper investigates interaction between trade liberalization in goods and liberalization in service FDI. Since some services are market-specific and have non-tradable nature, a foreign firm has a higher cost in service provisions compared to its domestic competitor and it can overcome the disadvantage by either outsourcing services to the domestic competitor or making service FDI. When the cost of service FDI is high enough, trade liberalization under service outsourcing may have an anti-competitive effect and benefit both domestic and foreign firms at the expense of consumers. A decline in the cost of service FDI makes this paradoxical effect less likely, and trade liberalization becomes pro-competitive when the cost is low enough so that the foreign firm actually makes service FDI.

要旨：While the most of the theoretical models of social networks are inherently dynamic, the majority of the existing empirical studies of the social networks are static. This paper is an attempt to enrich the field by providing an empirical analysis of evolving networks of successful R&D collaborations in the IT industry in the United States between 1985 and 1995. We first measure the properties of the network over time and demonstrate that the network has become more extensive, more clustered, and more unequal in the sense "star" companies have emerged in the network. We then estimate the strength of various mechanisms that have been proposed in the literature as driving forces behind the network evolution. After controlling for the similarity of firms as much as possible, including some unobserved similarities among firms by extracting the community structure defined within the network, we find there are significant "triadic closure bias" and "preferential attachment bias".