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...

Starting with Krugman (1980), much literature has analyzed how trade liberalization affects the economy based on the notion that trade is motivated by consumer’s love of variety. In this paper, I augment these preferences by the determinants of demand for heterogeneous products. The model...