【国際経済学セミナーと共催】
要旨：We propose and apply a new theory-consistent algorithm, which uses disaggregated inter-city trade data to identify a pyramidic city system with central places and associated hinterlands. Because central places possess more industries than the cities in their hinterlands, and because industries, which are exclusive to central places, are more likely to export to the small, peripheral cities in the central place’s hinterland, we find that aggregate exports from central places to their hinterlands are two to five times larger than predicted by gravity forces. Using a simple decomposition approach, we show that this upward bias results from aggregation along the extensive industry margin, which is why the bias is much smaller and only marginally significant if estimation is conducted in a theory-consistent way at the disaggregated industry level.

要旨：This paper investigates a two-location local public goods economy in which agents choose their residential location and consumption bundles, faced with location-specific disaster risks. The amount of local public goods provision financed by local wealth tax is determined by majority voting of residents to reduce the disaster probability. We show that every equilibrium is wealth stratified if utility functions are constant relative risk aversion with basic consumption in housing. Moreover, when disaster risks in a location increase, population and housing rent decrease and the tax rate increases in that location, while the opposite takes place in the other one. Using this framework, we also evaluate two different policies numerically, namely foreign aid and inter-jurisdiction transfer as a local public good or a lump-sum subsidy. If foreign aid provides local public goods for the riskier location, wealthier agents may move into that location and force poorer agents to move out, making the wealthier agents direct beneficiaries of this foreign subsidy. Furthermore, we find that the inter-jurisdiction transfer from the less risky location to the riskier one may harm the poorer by rising housing rents. Finally, the poorer agents may benefit more from a lump-sum subsidy.

要旨：This paper investigates the impact of high-speed rail on innovative activities of establishments along the rail. Using the case of the opening of Nagano-Hokuriku Shinkansen in Japan, and applying difference-indifferences approach, we estimate the impact of the high-speed rail on the innovative activities along the line. We find that after the opening the high-speed rail, innovative activities by the establishments along the line are significantly increased. Furthermore, collaborative patents across establishments along the line and citations of patents published by the establishments in Tokyo are increased. These imply that the innovative activities along the line is increased through knowledge diffusions from the nearby establishments and those in Tokyo.

要旨：Unlike most of the theoretical researches on economic geography, I assume consumers do not necessarily have access to all the varieties in the market, which motivates firms to compete one another for acquiring customers, and investigate the effects of such competition on economic geography. I first extend the general equilibrium model of monopolistic competition in the closed economy by assuming consumers’ limited access to varieties, and then apply it to the model with two regions. I show (1) the core region enjoys more varieties than the periphery, and (2) economic activities may disperse even at low trade costs when the competition for attention is fierce.

【国際経済学セミナーと共催】
要旨：This paper examines the impact of temperature changes on rural-urban migration using a 56km×56km grid cell level dataset covering the whole world at 10-year frequency during the period 1970-2000. We find that rising temperatures reduce rural-urban migration in poor countries and increase such migration in middle-income countries. These asymmetric migration responses are consistent with a simple model where rural-urban earnings differentials and liquidity constraints interact to determine rural-to-urban migration flows. We also confirm these temperature effects using country-level observations constructed by aggregating the grid cell level data. We project that expected warming in the next century will encourage further urbanization in middle-income countries such as Argentina, but it will slow down urban transition in poor countries like Malawi and Niger.

要旨：This paper investigates unit-level monthly dynamics of housing rents through periods of tenancy and vacancy, using a unique panel of rental units in Tokyo through 1996-2017. We find that (i) consistent overall rent stickiness is attributable to the small extensive margin (limited adjustment opportunity) and small intensive margin (rare adjustment at contract renewal stages); (ii) expanded rent gaps from market level during tenancies become small during vacancies; and (iii) rents exhibit time/state dependence during both tenancies and vacancies, while a specific relationship between a long-term tenant and an owner results in a discount during the tenancy.

要旨：When making a location decision, a firm considers only its own trading costs and ignores trading costs paid by trading partner firms. The exclusion of the latter is the source of locational externalities. We examine this locational externality in the Tokyo metropolitan area, using the actual trade networks. Results show (1) we classify what trade patterns involve locational externalities, (2) the ratio of trades involving locational externalities is about 8%, and (3) the transfer of a randomly-chosen 5% of firms to the center of Tokyo can generate external benefits of 0.13-0.21% in the total industry in terms of value added.