Measuring at purchasing-power parity makes the gap in GDP and living standards look narrower.

ECONOMIST: Economic folly

Earlier this year, staff at the Federal Reserve also marked down their estimate of the country's potential GDP and the output gap in response to the surprisingly steep drop in unemployment.

ECONOMIST: Free exchange

We're spending about 23 percent of GDP and we take in 18 percent of GDP, and that gap is growing, because health care costs -- Medicare and Medicaid in particular -- are growing, and we've got to do something about that.

WHITEHOUSE: President Obama Closes Forum on Jobs and Economic Growth