Greenspan came onto my radar screen in the late sixties as a seller of economic and financial advice to the investment industry. To be brutally honest, he was considered run of the mill by anyone I knew then or have met later who knew his service then. His high point in most memories, certainly mine, was a famous call in January 1973 that, “it is rare that you can be as unqualifiedly bullish as you now can,” a few days before a market decline of over 60% in real terms, second only to the Great Crash in a century, accompanied also by a bitter recession. This was one of the first of a long line of terrible prognostications for which he has remarkably not been remembered, except by a handful of us amateur historians. Then in the mid seventies he disappeared into some government job, of which I was barely aware, until he re-emerged with a bang in 1987, without as far as I can find having done anything documentably very well.
~ Jeremy Grantham, "Immoral Hazard," GMO Quarterly Letter, April 2008