Premium
Optimal Transport Networks in Spatial Equilibrium
Author(s) -
Fajgelbaum Pablo D.,
Schaal Edouard
Publication year - 2020
Publication title -
econometrica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 16.7
H-Index - 199
eISSN - 1468-0262
pISSN - 0012-9682
DOI - 10.3982/ecta15213
Subject(s) - social planner , convexity , planner , mathematical optimization , transport network , computer science , regular polygon , graph , general equilibrium theory , economics , microeconomics , mathematics , computer network , geometry , theoretical computer science , financial economics , programming language
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.