In the 1990s Greg Mankiw said that the Clinton tax increases would cause a major recession.
In fact, the tax increases were followed by a major boom.
In the early 2000s Greg Mankiw said the Bush tax cuts would cause an economic boom.
In fact, the tax cut was followed by the weakest economic expansion on record where the GDP Gap was never closed and for the first time in over 50 years the share of the working age population employed failed to surpass the previous peak.
Now, Greg Mankiw tells us to ignore our lying eyes and act on some obscure academic research that finds that Keynesian fiscal stimulus does not work.
I always believed in the old Samuelson statement that any economic concept you can not explain to your father-in-law will eventually be proved wrong. My father-in -law was a truck driver with an 8th grade education. I wonder if Mankiw, or others taking the same position, would care to explain in ways my father-in-law would understand why we should ignore the last 20 year history and follow his advice.