Heterogeneous Firms and Trade
---- Acknowledgments ----
We are grateful to Treb Allen, Costas Arkolakis, Ariel Burstein, Davin Chor, Arnaud Costinot, Swati Dhingra, Gene Grossman, Keith Head, Elhanan Helpman, Andrei Levchenko, Thierry Mayer, Gianmarco Ottaviano, Esteban Rossi-Hansberg and participants at the Handbook of International Economics conference in Cambridge, MA in September 2012 for helpful comments and suggestions. We are also grateful to Cheng Chen for research assistance. The authors are responsible for any remaining limitations. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.