"This article explores the impact of offshoring on productivity using firm-level data for the Japanese manufacturing industries during the period 1994-2000. We find that intrafirm offshoring, that is, sourcing of intermediate inputs to foreign affiliates within a particular multinational firm, has generally a positive effect on productivity of the offshoring firm, while arm's-length offshoring, that is, sourcing to unaffiliated foreign firms, does not have such an effect. In addition, the impact of arm's-length offshoring is negative for nonmultinationals and nonexporters but nonnegative for multinationals and exporters. These results suggest that the costs of searching foreign firms suitable for offshoring are nonnegligible". ("JEL" F14, L23) Copyright (c) 2008 Western Economic Association International.