This NY Times article had Greenspan's recent stuff about housing. But the stuff about risk caught my eye especially the last paragragh here.
...Alan Greenspan, the chairman of the Federal Reserve, warned on Friday that people have been unrealistic in believing that the economy has become permanently less risky.
the Fed chairman implicitly took aim at both the torrid run-up in housing prices and at the broader willingness of investors to bid up the prices of stocks and bonds and accept relatively low rates of return.
Both trends reflect what Mr. Greenspan said was the increased willingness of investors to accept low "risk premiums, a willingness based on a complacent assumption that the low interest rates, low inflation and strong growth of recent years are likely to be permanent."
"Any onset of increased investor caution elevates risk premiums and, as a consequence, lowers asset values and promotes the liquidation of the debt that supported higher prices," he said. "This is the reason that history has not dealt kindly with the aftermath of protracted periods of low risk premiums." ...
[Besides housing]* Mr. Greenspan was also alluding to a much broader pattern of economic behavior, an increased hunger among investors to look for higher profits wherever they might be and to pay higher prices for everything from bonds of Latin American nations to shares in risky hedge funds.