By Andrew Atkeson, Jonathan Heathcote and Fabrizio Perri
The US net foreign asset position has deteriorated sharply since 2007 and is currently negative 65 percent of US GDP. This deterioration primarily reflects changes in the relative values of large gross international equity positions, as opposed to net new borrowing. In particular, a sharp increase in equity prices that has been US-specific has inflated the value of US foreign liabilities. We develop an international macro finance model to interpret these trends, and we argue that the rise in equity prices in the United States likely reflects rising profitability of domestic firms rather than a substantial accumulation of unmeasured capital by those firms. Under that interpretation, the revaluation effects that have driven down the US net foreign asset position are associated with large, unanticipated transfers of US output to foreign investors.
This is a fascinating paper with very interesting results. However, I am afraid that some may draw the wrong policy lessons from it, for example limiting access of foreign investors to US markets. While it would likely “improve” the net foreign asset position, it would also restrict investment into the productive capacity of the US, and this is what matters in the end. A better policy would be to look into why the profits are so high and how that is welfare worsening.