This chapter focuses on the estimation and interpretation of gravity equations for bilateral trade. This necessarily involves a careful consideration of the theoretical underpinnings since it has become clear that naive approaches to estimation lead to biased and frequently misinterpreted...

We present a set of empirical regularities that characterize the export activity of firms. We decompose firm-level exports by product category across destination markets in a consistent manner for four data sets from Brazil, Chile, Denmark, and Norway. We relate the empirical regularities to new...

This paper develops a model of trade and CO2 emissions with heterogenous firms, where firms make abatement investments and thereby have an impact on their level of emissions. The model shows that investments in abatements are positively related to firm productivity and firm exports. Emission...

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...