Krugman doesn´t miss any opportunity to “harass” republicans even if to do so he has to take some “liberties” with the historical facts:
Reagan did not start an era of unprecedented growth by any measure: employment, GDP, productivity, whatever. But maybe the easiest way to see what didn’t happen is to look at median family income in constant dollars:
A spectacular increase during the high-tax, strong-union postwar generation; fitful improvement since, with the only sustained rise during the Clinton years. That’s the story; it’s amazing how many people don’t know it. (My bold)
Oh, by the way, GW Bush presided over pretty good productivity growth but terrible job growth, even before the recession. So the overall result was poor.
If you take a closer look at the facts, the “conclusion” changes quite dramatically: