Geography, Transportation, and Endogenous Trade Costs
构建了一个以海洋运输服务市场与商品贸易市场相互作用为核心的空间模型，利用船舶轨迹和运费数据估计模型，揭示运输部门如何削弱比较优势、产生网络效应并缓冲贸易冲击，为评估基础设施项目提供分析工具。
In this paper, we study the role of the transportation sector in world trade. We build a spatial model that centers on the interaction of the market for (oceanic) transportation services and the market for world trade in goods. The model delivers equilibrium trade flows, as well as equilibrium trade costs (shipping prices). Using detailed data on vessel movements and shipping prices, we document novel facts about shipping patterns; we then flexibly estimate our model. We use this setup to demonstrate that the transportation sector (i) attenuates differences in the comparative advantage across countries; (ii) generates network effects in trade costs; and (iii) dampens the impact of shocks on trade flows. These three mechanisms reveal a new role for geography in international trade that was previously concealed by the frequently‐used assumption of exogenous trade costs. Finally, we illustrate how our setup can be used for policy analysis by evaluating the impact of future and existing infrastructure projects (e.g., Northwest Passage, Panama Canal).