Mayer, ThierryMelitz, MarcOttaviano, Gianmarco I. P.2014-06-172014Mayer, Thierry, Marc J. Melitz, and Gianmarco I. P. Ottaviano. 2014. “ Market Size, Competition, and the Product Mix of Exporters.” American Economic Review 104 (2) (February): 495–536.0002-8282http://nrs.harvard.edu/urn-3:HUL.InstRepos:12330897We build a theoretical model of multi-product firms that highlights how competition across market destinations affects both a firm's exported product range and product mix. We show how tougher competition in an export market induces a firm to skew its export sales toward its best performing products. We find very strong confirmation of this competitive effect for French exporters across export market destinations. Theoretically, this within-firm change in product mix driven by the trading environment has important repercussions on firm productivity. A calibrated fit to our theoretical model reveals that these productivity effects are potentially quite large.en-USJournal Article2014-06-1710.1257/aer.104.2.495