The empirical failures of Krugman’s macroeconomic model

See Paul Krugman: Three Wrongs Don’t Make a Right by Robert P. Murphy of FEE. It was a long post so here is the conclusion:

"Krugman, armed with his Keynesian model, came into the Great Recession thinking that (a) nominal interest rates can’t go below 0 percent, (b) total government spending reductions in the United States amid a weak recovery would lead to a double dip, and (c) persistently high unemployment would go hand in hand with accelerating price deflation. Because of these macroeconomic views, Krugman recommended aggressive federal deficit spending.

As things turned out, Krugman was wrong on each of the above points: we learned (and this surprised me, too) that nominal rates could go persistently negative, that the US budget “austerity” from 2011 onward coincided with a strengthening recovery, and that consumer prices rose modestly even as unemployment remained high. Krugman was wrong on all of these points, and yet his policy recommendations didn’t budge an iota over the years.

Far from changing his policy conclusions in light of his model’s botched predictions, Krugman kept running victory laps, claiming his model had been “right about everything.” He further speculated that the only explanation for his opponents’ unwillingness to concede defeat was that they were evil or stupid."