Empirical studies of firms within industries consistently report substantial heterogeneity in measures of performance such as size and productivity. This paper explores the consequences of joint heterogeneity on the supply side (sellers) and the demand side (buyers) in international trade using...

Using a new and extensive micro data set we investigate the impact of a change in international competitive pressure following a real exchange shock on multi-product firms’ product mix. We only find weak evidence for the core competencies hypothesis, according to which, we would expect the...