Optimal Transport Networks in Spatial Equilibrium

• 成果类型: Article
• 署名作者: Fajgelbaum, Pablo D.; Schaal, Edouard
• 署名单位: University of California System; University of California Los Angeles; National Bureau of Economic Research; Centre de Recerca en Economia Internacional (CREI); Pompeu Fabra University; Barcelona School of Economics; Center for Economic & Policy Research (CEPR)
• 刊物名称: ECONOMETRICA
• ISSN/ISSBN: 0012-9682
• DOI: 10.3982/ECTA15213
• 发表日期: 2020
• 页码: 1411-1452
• 关键词: trade; roads; infrastructure; distortions; gains; COSTS; time

摘要

We study optimal transport networks in spatial equilibrium. We develop a framework consisting of a neoclassical trade model with labor mobility in which locations are arranged on a graph. Goods must be shipped through linked locations, and transport costs depend on congestion and on the infrastructure in each link, giving rise to an optimal transport problem in general equilibrium. The optimal transport network is the solution to a social planner's problem of building infrastructure in each link. We provide conditions such that this problem is globally convex, guaranteeing its numerical tractability. We also study cases with increasing returns to transport technologies in which global convexity fails. We apply the framework to assess optimal investments and inefficiencies in the road networks of European countries.