The U.S. Economy's Top Speed Has Probably Been Overestimated for Years

Revisions to the U.S. gross domestic product since 2011 reinforce the shift to a slower era of economic growth and underscore the difficulties the Federal Reserve faces in gauging just when to inch interest rates away from the zero-lower bound.

According to the Bureau of Economic Analysis, real GDP from 2011 to 2014 increased at an annual rate of 2 percent, a downgrade from the prior estimate of 2.3 percent.