Comparative Advantage and Heterogeneous Firms

This paper presents a model of international trade that features heterogeneous firms, relativeendowment differences across countries, and consumer taste for variety. The paper demonstrates thatfirm reactions to trade liberalization generate endogenous Ricardian productivity responses at theindustry level that magnify countries' comparative advantage. Focusing on the wide range of firmlevelreactions to falling trade costs, the model also shows that, as trade costs fall, firms incomparative advantage industries are more likely to export, that relative firm size and the relativenumber of firms increases more in comparative advantage industries and that job turnover is higher incomparative advantage industries than in comparative disadvantage industries.