Exchange rate movements can have large effects on the measured NIIP. For example, the current account deficit in 2007 was about $730 billion, which means we borrowed around 3/4 of a trillion dollars from foreign countries in 2007 alone. Naturally this causes the NIIP to decline: the world's largest debtor country goes more deeply into debt. However, the dollar depreciated almost 10% during the year, and most US assets held abroad are denominated in foreign currency. The BEA estimates a resulting rise in the dollar value of these assets of almost $440 billion, which it adds to the US NIIP.

The net international investment position (NIIP) of a country is the stock of the net claims of that country vis a vis the rest of the world. Roughly, it is our claims on them minus their claims on us. For the US, the NIIP was very positive at the beginning of the 1980s. This reflected past net saving the US had done vis a vis the rest of the world. According to BEA data, by the end of the 1980s this accumulated saving had not only been exhausted, but the US had gone substantially into debt. The same data suggests the net US debt to the rest of the world is currently about 2.5 trillion dollars.