要旨：橘木らによって提起された所得格差論争では、所得再配分調査や全国消費実態調査などの全国値がもとになっており、地域間の所得格差が全く考慮されていないか、都道府県単位の言及にとどまっている。 本報告では、1983～2003年住宅・土地統計調査のデータを用いて、バブル期前後の東京大都市圏と京阪神大都市圏における距離帯別所得分布を検討し、所得格差から見た都市圏の空間構造の変化を明らかにする。

要旨：地域的なイノベーションのメカニズムとして有効な産業クラスターの形成を図る上で、どの点に注目したら良いであろうか。本稿は、企業、大学など様々な構成員の中で、製品化、事業化の担い手である企業に注目する。中でも、地域性のある存在として中小企業に注目して、どのような中小企業に注目することが産業クラスターの形成に有効であるかを考察する。その方法としては、「産業クラスター計画」の先進事例として位置づけられているTAMAを事例として、同地域の企業アンケート調査から得られたデータによる計量分析に基づいて、「製品開発型中小企業が、産学連携及び企業間連携（ 新技術・新製品の開発を目的とするもの）を有効に活用しており、従って、産業クラスター形成の有力な担い手となりうる」ことを検証する。あわせて、産学連携、大企業と中小企業の連携、中小企業間の連携の機能の比較を行う。

要旨：It is often argued, though mostly informally, that outward foreign direct investment (FDI) is a synonym for the export of employment and thus detrimental to the home economy. To see whether and under what conditions this intuition indeed holds true, we construct a model of unionized duopoly and examine welfare implications of outward FDI on the home country. It is found that the presence of domestic competition gives rise to effects which have critical bearings on social welfare. There are two main findings. First, due to strategic interactions between the unions, the welfare effect of FDI can be negative, even when we disregard the fixed cost of FDI. Second, this negative effect arises more at the expense of consumers, rather than the unions: in fact, quite contrary to the popular belief, FDI may actually benefit the unions because it serves to soften price competition between them. The analysis reveals that the welfare effect of outward FDI hinges critically on the nature of domestic competition, especially among input suppliers, and their bargaining power against their respective downstream producers.

要旨：This paper examines how the decline of communication costs between management and production facilities within firms and the decrease in trade costs of manufactured goods affect the spatial organization of a two-region economy with multi-unit・multi-plant firms. The development of information technology decreases the costs of communication and trade costs. Thus, the fragmentation of firms is promoted. Our result indicates that, with decreasing communication costs, firms producing low trade-cost goods (such as electronics products) tend to concentrate their manufacturing plants in low wage countries. In contrast, firms producing high trade-cost products (such as automobiles) tend to have multiple plants serving to segmented markets, even in the absence of wage differentials.

要旨：This paper proposes a framework where commercial activities emerge endogenously through merchants' market-oriented investments. Merchants buy goods from producers by offering the bid-price, and hold them as an inventory for sale to consumers by setting the ask-price. Competition amongst merchants generates a tradeoff, when they expand business, in which excess inventories entail a loss from their remaining unsold while a deficit of stock loses a sale foregone. The steady-state equilibria are shown to display an interesting multiplicity in which the optimal level of merchants' inventory holdings interacts with the bid-ask spread or the markups. In more commercialized equilibria, merchants are large-scaled, attract a large number of consumers, and restock inventories by a low price, while in less commercialized equilibria, merchants are small-scaled, attract only few consumers, and restock inventories by a high price. We show that producers, who are less skillful in selling goods, attract inefficiently large number of buyers in the latter equilibria than in the former, and thereby that the division of labor between production and commerce enhances the allocation efficiency and overall welfare. We find that such a division of labor can be limited by the extent of the total size of market. Further, producers' decision to become merchants will also be discussed.

要旨：We study an equilibrium for a product-differentiated market in which oligopolistic firms and monopolistically competitive firms coexist. We assume that the number of monopolistically competitive firms changes given the number of oligopolistic firms and the equilibrium size is determined when no firms earn positive profits. We show that there may exist multiple equilibria, and the size of monopolistically competitive firms decreases and social welfare level increases as the number of oligopolistic firms increases.

要旨：Though road pricing equal to social marginal cost is the best instrument to reduce the congestion, it is considered as impractical one by political reason. Thus instrument to shift the auto uses to other modes is one of alternatives. In this paper, we investigated optimal bus services regarding fare and frequency under constraint of real world, where auto is under-priced. And bus services under the zero profit constraint and under the provision by monopolistic operator were also investigated. We showed that even though optimal bus fare depends on the type of bus provision, the optimal rule to determine the bus frequency is same. Furthermore recent experience in London gives rise to the policy questions about the bus service policy. Thus by comparative analysis, we investigated that how the optimal bus service should change against the increase in road toll. We showed that bus fare should increase when toll level gets increased except the case of zero profit constraint. And we also showed that optimal bus frequency and load factor increase regardless of types of provision.

要旨：Despite the airport privatization and deregulation trend in recent years, whether or not the privatized or commercialized airports should be left unregulated is still an open question. Related to this issue, one question that has received a very little attention to date is if and how pricing behavior of unregulated airports affect downstream airline competition, especially the competition between airlines offering differentiated services such as the case of full service airlines (FSA) vis-à-vis low cost carriers (LCC). If the upstream monopoly (airport) hinders downstream (airline) competition, the welfare effects of the upstream unregulated monopoly may be much larger than initially suspected. This aspect of airport pricing has not been formally incorporated in the debate on airport price regulation. In this paper, we study a duopoly model to capture the differential competitive effects of changing airport user charges on FSAs and LCCs. By making reasonable assumptions on differential price elasticities, unit costs and competitive behavior as manifested by firm-specific conduct parameters, we perform numerical simulations to measure differential effects on an FSA and an LCC of increasing airside user charge by an unregulated upstream monopolist airport. Our analytical and numerical results suggest existence of the asymmetric effects of an airport’s monopoly pricing on LCC and FSA. That is, LCCs suffer more from an identical cost increase than FSAs and are, therefore, more vulnerable to monopolistic pricing practices of an unregulated airport. This implies that unregulated airport pricing would reduce the extent of competition in downstream airline markets, and thus, cause a further detrimental effect on welfare over and above the first-order dead weight loss of airport’s monopolistic pricing. Considering that LCCs have brought considerable reduction of average fares and the associated welfare gains, it is important for the governments to take into account of these asymmetric effects of increasing airport user charges on FSAs and LCCs when they consider the form and extent of regulation or deregulation. Although our model and simulation work deal specifically with the effect of airport pricing on downstream airline markets, our framework of analysis may be applicable to analysis of any policy affecting costs of FSAs and LCCs including security levies as well as potentially adaptable to other upstream-downstream industry cases.

要旨：本報告が依拠するモデルでは、非熟練労働者が技能労働者になるには固定費用が発生するため、規模の経済が存在する。しかし多くの技能労働者があつまる場所では、固定費用が軽減され、追加的な技能労働者形成がより容易になる。技能労働者を雇用する近代産業は技能労働者のバラエティの拡大によって生産コストが低下する外部効果を得る。一方、技能労働者が多くなれば、彼らの間の競争が増すので収入は逓減し、非熟練労働者が相対的に不足してくるので実質賃金格差は縮まる。これを２地域空間に適用すると、技能労働者が雇用される近代産業がどちらか一方に集中する核－周辺構造が成立することが確認される。周辺地域で近代産業を設立しようとしても、各地域の集積の経済が強く、低賃金だけでは十分な競争力を有さないからである。技能労働者が育っていない周辺地域で技能労働力を養成する固定費用の高さも障害になる。ただし、地域を越えて技能のスピルオーバーがある場合に、これを利用して技能労働力を涵養して、そのような障壁を乗り越える可能性は高まる。

要旨：出発時刻選択問題における動的な均衡状態の導出方法、均衡状態と最適状態の関連、均衡状態の存在についての定理とそれらの関連を示す。出発時刻選択問題は道路における渋滞を費用最小化原理と均衡状態を前提として理論的に解析するための枠組みであり、これまでいくつかの研究により解法が示されている。しかしこれらの研究では費用関数に強い制約が課せられていた。この研究では、利用者の選択する経路上に存在するボトルネックが１つだけしかない場合において、費用関数の前提条件を緩和した上で出発時刻選択問題の解法および均衡状態のもつ数理的な性質を示す定理を導出する。