Taxing multinationals in a world with portfolio flows and R&D: Is capital export neutrality obsolete?

This paper examines recent claims that capital export neutrality no longer serves as an effective principle for the taxation of income from foreign direct investment, due to the large and growing role played by portfolio capital in financing investment and to the recognition that R&D is an important determinant of international trade and investment. In our evaluation of these claims, we find capital export neutrality appears robust. Because both domestic and foreign activities may be financed with portfolio capital, and they both produce goods that compete in the world economy, there is no compelling reason to grant a lower tax to foreign income alone. Regarding the promotion of R&D or the entry of new competitors, cutting the tax on foreign income may be no more effective than cutting the tax on domestic income. A second focus of the paper is to calculate what the residual U.S. tax rate on active foreign income actually is. Based on 1990 data this rate is negative if foreign income is defined appropriately.