A Note on Detecting Learning by Exporting

Learning by exporting refers to the mechanism whereby firms improve their performance (productivity) after entering export markets. Although this mechanism is often mentioned in policy documents, a significant share of econometric studies has not found evidence for this hypothesis. This paper shows that the methods used to come to the latter conclusion suffer from a large internal inconsistency: they rely on an exogenous evolving productivity process. I show how recent proxy estimators can accommodate endogenous productivity processes such as learning by exporting. I rely on my framework to discuss the bias introduced by ignoring such a process and how adjusting for it can lead to detect significant productivity gains upon export entry. I estimate my model on standard firm-level data and find substantial additional productivity gains from entering export markets.