We derive a simple equation for the welfare gains from trade when tariffs are liberalized or iceberg trade costs fall. Covering various one-sector trade models that may or may not feature extensive margins and imperfect competition, we generalize the analysis of Arkolakis, Costinot and...

This paper endogenizes the spatial distribution of infrastructure investment and transportation costs. Transportation costs between two addresses depend on cumulative infrastructure investment. In a continuous space setting with several independent countries or regions, consumers demand domestic...