Does importing more inputs raise exports? Firm level evidence from France

Following Melitz (2003)'s seminal paper, several theoretical and empirical studies have shown that only the subset of most productive firms export. While other studies provide evidence on a positive effect of an increase in imported inputs on firms' productivity, the link between imported intermediate inputs and export scope has not been made. This paper bridges the gap by studying the impact of imported inputs on the margins of exports. We use a unique firms' level database of imports at the product (HS6) level provided by French Customs for the 1995-2005 period. Access to new varieties of inputs may increase productivity, and thereby exports, through better complementarity of inputs, transfer of technology and/or decreased inputs price index. We test for these different mechanisms by distinguishing the origin of imports (developing vs. developed countries) and constructing an exact price index a la Broda and Weinstein (2006). We find a significant impact of higher diversification and increased number of imported inputs varieties on firm's TFP and export scope. Whereas the complementarity and transfer of technology mechanisms are supported by our results, the price effect seems very limited.