A money manager, Bill Fleckenstein, co-authored a book titled Greenspan's Bubbles: The Age of Ignorance at the Federal Reserve. (You can read a review here.) In the book, he makes a pretty convincing that Alan Greenspan contributed to the stock bubble of the 1990s and the real estate bubble of this decade by not taking appropriate actions. Actions like raising the interest rate in the 1990s; raising the amount that a stock purchaser had to deposit with a stock broker when buying on margin; and by allowing the creation of novel mortgage instruments.
They point out that the United States had gone from the stock market crash of 1929 to 1979 without a speculative bubble. Then, from 1980 to the present time, there have been three bubbles. One in real estate in the late 1980s that caused the collapse of the savings and loan industry, and the two mentioned above. All of which happened on Greenspan's watch.
The authors argue that a lot of the problems were caused by Greenspan's arrogance in thinking that he knew more than most people, by his belief that he was "the smartest guy in the room." There could be other reasons, however. Could it be that Greenspan was pursuing policies that he thought would benefit the presidents who appointed him?
While George H.W. Bush lost his re-election in 1992, both Bill Clinton and George W. Bush won re-election. In both administrations, however, toward the end of their second terms, financial clouds loomed on the horizon, although obviously much worse in Bush's case than in Clinton's.
In any event, no matter what his motivations, Fleckenstein and his co-author make a compelling case that far from being a good thing, Greenspan's time at the Federal Reserve had very bad consequences for most Americans.