We develop a model to estimate simultaneously import shares, export shares, outward foreign direct investment and domestic profits for a large sample of U.S. manufacturing industries. In our model, trade barriers alter the ability of domestic market structure to influence domestic performance. The results indicate that trade flows behave as expected in response to factor intensity. Profits are disciplined by imports and enhanced by exports. Concentration reduces both import and export shares but economies of scale increase them. Exports are complements rather than substitutes for foreign direct investment.