The United States became a net foreign debtor in 1985. With current account deficits every year since that net foreign indebtedness has steadily increased since, reaching a reported total of -$10.56 trillioin as of Sept. 30 this year, a substantial total.
However, while many have long predicted that this mounting net foreign indebtedness would eventually lead to the US having also having a net negative capital income flow, it has not happened. In 1985 when the US initially into net indebtedness, the US had a net surplus on capital income of about $30 billion. Rather than shrinking, that surplus has increased somewhat apparently in the subsequent 34 years. As of the second quarter of this year it appears that the annual surplus of capital income was running in the neighborhood of $100 billion.
While there are serious sources of uncertainty and noise in much of this data, it certainly seems that US-owned assets abroad are earning far higher rates of return than what foreigners are earning from their assets in the US. This has for quite a long time been labeled the "dark matter" phenomenon.
The question arises: how long can this odd situation continue?