The Geographic Effects of Trade Liberalization with Increasing Returns in Transportation
构建经济地理模型，分析贸易自由化如何改变经济活动分布，发现运输规模报酬递增可能导致人口向单一特大城市集中，进而因拥堵成本降低福利。
Abstract This paper develops a model of economic geography that examines how the distribution of economic activity may change as a country opens up to foreign trade. The distinctive features of the model are that transportation is costly between locations within a nation as well as between nations, and that these transportation costs are subject to increasing returns to scale. A result of the model is that trade liberalization may cause the population of a country to become more concentrated in a single megalopolis. The large megalopolis may reduce welfare due to congestion costs, which implies that liberalization may unexpectedly leave the country worse off.