WHICH WOULD EXPLAIN THE GLOBAL SLOWDOWN:

[T]he world's investors declared loud and clear in 2008 that they were not concerned about the sustainability of US deficits. When the global financial crisis erupted, they flooded into dollar assets, even though the crisis originated in the United States.

Moreover, a substantial amount of US adjustment has taken place since 1982 - for example, the dollar depreciations of 1985-1987 and 2002-2007 and the fiscal retrenchments of 1992-2000 and 2009-2014. The big increase in domestic output of shale oil and gas has also helped the trade balance recently.

As a result, the US current-account deficit in 2013 had narrowed by half in dollar terms from its 2006 peak, and from 5.8% of GDP to 2.4%. This is a decline of two-thirds when expressed as a share of global output.

A symmetric adjustment has also occurred in China, via real appreciation of its currency and higher prices for labor and land. China's current-account surplus peaked in 2008 at more than 10% of GDP and has since narrowed dramatically, to 1.9% last year. China's trade adjustment in some respects followed that of Japan, the original focus of American trade anxieties in the 1980s.

I propose a third, more speculative reason why it may be time to stop worrying about the US current-account deficit. It is possible that, properly measured, the true deficits were smaller than has been reported, and even that, in some years, they were not there at all.

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