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...

There is strong evidence that different income groups consume different bundles of goods. This evidence suggests that trade liberalization can affect welfare inequality within a country via changes in the relative prices of goods consumed by different income groups (the price effect). In this...

This paper presents a simple model of monopolistic competition that features a general class of additively separable preferences without any fixed costs. While trade always crowds out less productive firms as long as countries are symmetric, we show that the impact is independent of entry/exit a...

In this paper, I investigate welfare gains associated with trade induced intra-firm adjustments of multi-product firms. To disentangle the welfare gains, I split up the R&D portfolio of a multi-product firm into three different channels: i) product innovation, ii) investments in the degree of...