What explains the US net income balance?

Despite a significant deterioration in the US net foreign asset position, there has not been a corresponding deterioration in the net income balance. In fact, there has generally been a net income surplus. Two factors have been particularly important for the positive net income balance over the past 15 years or so. The first is that the United States has a positive net external equity balance and a negative net external debt balance. This contributes to a net income surplus because the income yield on equity has been higher than the income yield on debt. The second factor is that the United States earns a persistently higher income yield on its foreign direct investment (FDI) assets than foreigners earn on their direct investments in the United States. This paper summarises the evidence from firm-level studies and time-series data for the United States, as well as cross-country comparisons, to weigh up alternative explanations for this outcome. The evidence presented suggests that differences in income yields on FDI are not explained by the presence of large stocks of unmeasured assets. Moreover, they do not appear to be related to different characteristics of the investment such as industry composition or riskiness. There is some evidence that differences in the average maturity of investment have had some effect on yield differentials, especially in the 1980s. There are also incentives to minimise taxes that are consistent with the relatively low income yields earned on FDI in the United States, but no firm evidence that this is an important explanation.