During the last half of the 1990s, real gross domestic investment rose as a fraction of real GDP. This resulted from the rise in U.S. productivity and the related rise in the real yield on U.S. assets. This drew additional private capital from abroad. If the twin deficits theory is correct, it has an adverse implication for the efficacy of fiscal policy as a stimulus tool. It suggests that in an environment of highly mobile international capital flows the effect of policy induced increases in the structural budget deficit (e.g., tax cuts) on short-run economic growth would be largely offset by increases in the trade deficit. The experience during both the 1980s and 1990s demonstrates that a large and growing trade deficit need not be an impediment to overall job creation even though it may have had an effect on the type of jobs that were created since it affected the composition of U.S. output.