The existence of firms with different levels of efficiency within a country plays an important role in this in-depth analysis of industrial and trade policies in a multi-country trade-theoretic framework. Sajal Lahiri and Yoshiyasu Ono examine various industrial policies, R&D subsidies and trade policies under conditions of imperfect competition in a product market created by the presence of Cournot oligopolistic interdependence in production. The book covers commodity trade (assuming full employment) and foreign direct investment (assuming unemployment) making it of interest to researchers, advanced students and policy makers.