Intrafirm trade and vertical fragmentation in U.S. multinational corporations

Using firm-level data, we document two new facts regarding intrafirm trade and the activities of the foreign affiliates of U.S. multinational corporations. First, intrafirm trade is concentrated among a small number of large affiliates within large multinational corporations; the median affiliate ships nothing to the rest of the corporation. Second, we find that the input-output coefficient linking the parent's and affiliate's industries of operation - a characteristic commonly associated with production fragmentation - is not related to a corresponding intrafirm flow of goods.