now hawking on radio and television shows everywhere.

"The book, which I have not read, is ostensibly Greenspan's wisdom about the economy and economics. But he also tells us that his problem as Fed chair was that he just didn't know about the flood of junk mortgages that was fueling the unprecedented rise in house prices during the bubble years. He has used this ignorance to explain his lack of action – or even concern – about the risks posed by the bubble.

"Greenspan's 'I didn't know' excuse is so absurd as to be painful. The explosion of exotic mortgages in the bubble years was hardly a secret. It was frequently talked about in the media and showed up in a wide variety of data sources, including those produced bythe Fed. In fact, there were widespread jokes at the time about 'liar loans' or 'Ninja loans'. The latter being an acronym for the phrase, 'no income, no job, no assets'.

"The fact that banks were issuing fraudulent mortgages by the millions, and that the Wall Street crew was securitizing them as fast as they could get them, was not top secret information available only to those with special security clearance. This was the economy in the years 2002-2006.

"It was impossible to look at the economy in these years and not see the role of the housing bubble and the tsunami of bad mortgages that fueled it. The run-up in house prices led to a near record pace of construction. Typically housing construction is around 4.5% of GDP. It