Greenspan's tenure has illustrated an axiom to which his successor, Ben Bernanke, should subscribe: Minimalist missions by government produce maximum results. He has not defined the Fed's primary purpose as achieving this or that level of employment or economic growth. Rather, its mission is to preserve the currency as a stable store of value -- to control inflation. However, Greenspan's impeccable credentials as an inflation-fighter have enabled him to keep inflation rates low even during very low unemployment without kindling inflationary expectations, which can be self-fulfilling.
America's economy is so dynamic that in any five-year period, approximately 45 percent of Americans move from one income quintile to another. Twenty percent move up from the bottom quintile in any 12-month period, and 40 percent to 50 percent move up over 10 to 20 years. Because of the constant transformation of dynamic economies, the study of economics has become a science of single instances. Its practitioners are constantly in uncharted waters, reasoning inferentially. Just as astronomers inferred the existence of Pluto from the behavior of known planets, Greenspan inferred a rate of productivity growth higher than most estimates because inflation and unemployment were falling simultaneously.
The Federal Reserve system -- to give the devil his due, it is one of Woodrow Wilson's unregrettable undertakings -- annoys some populists who think every U.S. senator and representative should write on his or her bathroom mirror, and read every morning, this thought: ``The Fed is a creature of Congress." Indeed, Congress made it and could dictate to it -- could dictate interest rates and the money supply. A terrifying thought.
Greenspan's famously, at times hilariously, circumspect rhetoric has been prudent because some word, or inflection, or even arched eyebrow could have caused vast sums to slosh in this or that direction in capital markets. His rhetorical style -- or perhaps anti-style -- is a high-stakes illustration of Voltaire's idea that men use speech to conceal their thoughts.
Greenspan's wife has said he had to propose marriage three times before she understood what he was saying. And he was being droll when he said -- if he said it; apocrypha collect around legends -- that ``if I have made myself clear I have misspoken." His achievements speak clearly for him.