【京都大学大学院経済学研究科・国際経済学セミナーと共催】 要旨：What determines the distributions of skills, occupations, and industries across cities? We develop a theory to jointly address these fundamental questions about the spatial organization of economies. Our model incorporates a system of cities, their internal urban structures, and a high-dimensional theory of factor-driven comparative advantage. It predicts that larger cities will be skill abundant and specialize in skillintensive activities according to the monotone likelihood ratio property. We test the model using data on 270 US metropolitan areas, 3 to 9 educational categories, 22 occupations, and 21 manufacturing industries. The results provide support for our theory's predictions.

要旨：This paper investigates how airport congestion pricing affects airline network choices. Highlighting a network that links three congestible public airports and adopting a vertical structure approach, we show that governments can use take-off and landing charges to lead an airline to choose between a hub-spoke (hub) and point-to-point (ptp) network that maximizes social welfare. Given that the hub network uses large aircraft, socially optimal charges set below airport operating costs can lead the airline to choose this network even when the (potential) hub airport is more congested than local airports. When the hub network is chosen, the total subsidy required is almost always smaller than that of a ptp network. This also yields that the hub network is socially preferable from the perspective of subsidies. In addition, asymmetric congestion degrees and complementary relationships among the airports can result in the optimal charges of some airports to be positive.

要旨：City size distributions are known to approximately follow Zipf’s law, or more generally a common power law (CPL), across many countries. The most popular explanation for this regularity has been given by random growth models (e.g., Gabaix, 1999; Duranton, 2006, Rossi-Hanseberg and Wright, 2007), in which the power law results from the common iid growth rate of all cities. Since each subsample of cities has exactly the same properties, it also follows the same power law asymptotically without any role played by geography. The objective of the present paper is to establish counter-evidence from the US and Japan that the geography does indeed matter for CPL to hold among different regions and countries. Specifically, we show that random subsamples of cities taken from geographically connected regions are significantly more consistent with CPL than fully random subsamples. Furthermore, the sets of cities in economically meaningful regions (based on interregional trade) are even more significantly consistent with CPL. Finally, we present preliminary evidence that our finding is consistent with a class of central place models (Hsu, 2013, Akamatsu et al., 2013) in which sizes and locations of cities are determined through the spatial coordination of many industries subject to different degrees of scale economies.