Was the Economy of the 1990s a New One.

摘要

The miracle of U. S. economic performance in the late 1990s was a source of pride at home, of envy abroad, and of puzzlement among economists and policymakers. The Federal Reserve presided over quarter after quarter of output growth so rapid as to break any speed limit believed to be feasible as recently as 1997. As the unemployment rate inched ever lower, reaching 3.9 percent in April, 2000, the Fed reacted with a degree of neglect so benign that early in the year 2000 short-term interest rates were no higher than they had been five years earlier and long-term interest rates were considerably lower. Policy reactions were different in the late 1990s because the economy appeared to have experienced a sharp change in behavior along at least two dimensions. Unemployment could be allowed to decline, because throughout 1998 and 1999 inflation not only failed to accelerate in response to the continuing decline in unemployment but actually decelerated. This called into question the continuing relevance of the Phillips curve, the longstanding mainstream view that unemployment could not be allowed to fall below the natural rate or 'NAIRU', for that would inevitably be accompanied by an acceleration of inflation.1 The second change of behavior was in the growth of productivity. After resigned acceptance of the so-called 'productivity slowdown', more than two decades following 1973 when output per hour grew at barely one percent per annum, analysts were astonished to observe productivity growth at a rate of nearly three percent as the average annual rate for 1996-99 and an unbelievable 5.9 percent annual rate in the last two quarters of 1999.