The NBER Digest on the work of Robert C. Feenstra, Benjamin R. Mandel, Marshall B. Reinsdorf, and Matthew J. Slaughter:

In the past decade, the U.S. economy clearly enjoyed faster productivity growth than in previous time periods. The authors suggest that the magnitude of this acceleration has been overstated, with a sizable share of the gains actually being accounted for by the benefits of international trade. Their findings indicate that from 1995 through 2006, the actual average growth rates of the price indexes for U.S. imports are 1.5 percent per year lower than the growth rate of price indexes calculated using official methods. Thus, properly measured terms-of-trade gains can account for close to 0.2 percentage points per year, or about 20 percent, of the apparent increase in productivity growth for the U.S. economy over this period.