Greenspan's Ford years, not the Fed, defined his public service

One early piece of academic work foreshadowed James Tobin's Q theory of investment, a tool for estimating whether a business or market is overvalued. Tobin's 1981 Nobel citation noted the insight.

Greenspan had qualms about joining the Nixon administration. He opposed the 1971 price and wage controls. He told Nixon's chief of staff, Al Haig, that he would quit if Nixon went too far. Nixon resigned before Greenspan took the CEA post.

Ford was different. "He always acted as though we were equals, which was quite remarkable," Greenspan said.

The Fed came in 1987. Greenspan served five consecutive terms under Ronald Reagan, George H.W. Bush, Bill Clinton and George W. Bush. His tenure coincided with rising U.S. prosperity, the fall of the Soviet Union, China's opening, and the shift from fiscal to monetary policy as the primary macroeconomic tool.

Central bankers became public figures. Greenspan seemed to relish the attention at first. Later he described it differently. "I did what I had to do, and I made decisions when I had to make them," he said in 2016. "I could argue with senators when I had to go up to Capitol Hill, and I held my own very well because I knew a lot more than anybody up there. It wasn't an enjoyable function since none of the people were analytical or conceptual. They had opinions without any reasoning."

His light regulatory hand in financial markets drew criticism after the 2008 crisis. Greenspan acknowledged the failure. "Each of us has a model in our heads; some of them work, and some of them don't," he said. "What you need to measure is continuously evolving. I know that because the Federal Reserve had an extraordinarily good and very sophisticated model, it did not capture what was wrong that led to the crisis in 2008."

Greenspan was often called arrogant. He described himself differently: an introvert, the "side man" in a dance band, reading scores written by other people. The whole world ended up trying to read him.