Paul Krugman: An Economic Legend

"Here's a sample version of the legend: according to a recent article in The Washington Times, Ronald Reagan "crushed inflation along with left-wing Keynesian economics and launched the longest economic expansion in U.S. history." Actually, the 1982-90 economic expansion ranks third, after 1991-2001 and 1961-69 — but even that comparison overstates the degree of real economic success.
The secret of the long climb after 1982 was the economic plunge that preceded it. By the end of 1982 the U.S. economy was deeply depressed, with the worst unemployment rate since the Great Depression. So there was plenty of room to grow before the economy returned to anything like full employment.
The depressed economy in 1982 also explains "Morning in America," the economic boom of 1983 and 1984. You see, rapid growth is normal when an economy is bouncing back from a deep slump. (Last year, Argentina's economy grew more than 8 percent.)
And the economic expansion under President Reagan did not validate his economic doctrine. His supply-side advisers didn't promise a one-time growth spurt as the economy emerged from recession; they promised, but failed to deliver, a sustained acceleration in economic growth.
Inflation did come down sharply on Mr. Reagan's watch: it was running at 12 percent when he took office, but was only 4.5 percent when he left. But this victory came at a heavy price. For much of the Reagan era, the economy suffered from very high unemployment. Despite the rapid growth of 1983 and 1984, over the whole of the Reagan administration the unemployment rate averaged a very uncomfortable 7.5 percent.
In other words, it all played out just as "left-wing Keynesian economics" predicted." "