From the American Institute for Economic Research:
If there was any “irrational exuberance” in the market place, as Greenspan called it during the boom years that have now ended, the responsibility lies with Federal Reserve System over which he was the chairman until the end of January 2006.
With the financial markets awash in Fed-created money, credit-worthy standards were lowered, “inventive” financing was introduced to make it possible for the credit-unworthy to obtain home loans, and for others to have access to large sums of money for speculative buying at low margins.
Greenspan was certainly right that an uncertain future makes it difficult to predict when speculative bubbles will burst. But it was not unpredictable to know that years of easy monetary policy and accompanying near zero or negative real interest rates were creating an unsustainable boom that was setting the stage for an inevitable great crash.
Greenspan will eventually rival Arthur Burns and Daniel Crissinger as the worst Fed Chairman in history.