“The U.S. economy is running at its full potential for the first time in a decade, a new milestone for an expansion now in its ninth year,” The Wall Street Journal reports. But the milestone was reached, in part, because the Congressional Budget Office has, over the last 10 years, downgraded its estimate of the economy’s potential output. “Some economists think more slack remains in the job market than October’s 4.1% unemployment rate would suggest. Also, economic output is still well below its potential level based on estimates produced a decade ago by the CBO.”