“Aren’t you concerned with such a growing concentration of wealth that if one of these huge institutions fails that it will have a horrendous impact on the national and global economy?” asked Representative Bernard Sanders, an independent from Vermont.
“No, I’m not,” Mr. Greenspan replied. “I believe that the general growth in large institutions have occurred in the context of an underlying structure of markets in which many of the larger risks are dramatically — I should say, fully — hedged.”
The House overwhelmingly passed the bill that kept derivatives clear of C.F.T.C. oversight. Senator Gramm attached a rider limiting the C.F.T.C.’s authority to an 11,000-page appropriations bill. The Senate passed it. President Clinton signed it into law.
Still, savvy investors like Mr. Buffett continued to raise alarms about derivatives, as he did in 2003, in his annual letter to shareholders of his company, Berkshire Hathaway.
“Large amounts of risk, particularly credit risk, have become concentrated in the hands of relatively few derivatives dealers,” he wrote. “The troubles of one could quickly infect the others.”
But business continued.
And when Mr. Greenspan began to hear of a housing bubble, he dismissed the threat. Wall Street was using derivatives, he said in a 2004 speech, to share risks with other firms.
Shared risk has since evolved from a source of comfort into a virus. As the housing crisis grew and mortgages went bad, derivatives actually magnified the downturn.
The Wall Street debacle that swallowed firms like Bear Stearns and Lehman Brothers, and imperiled the insurance giant American International Group, has been driven by the fact that they and their customers were linked to one another by derivatives.
In recent months, as the financial crisis has gathered momentum, Mr. Greenspan’s public appearances have become less frequent.
His memoir was released in the middle of 2007, as the disaster was unfolding, and his book tour suddenly became a referendum on his policies. When the paperback version came out this year, Mr. Greenspan wrote an epilogue that offers a rebuttal of sorts.
“Risk management can never achieve perfection,” he wrote. The villains, he wrote, were the bankers whose self-interest he had once bet upon.
“They gambled that they could keep adding to their risky positions and still sell them out before the deluge,” he wrote. “Most were wrong.”
No federal intervention was marshaled to try to stop them, but Mr. Greenspan has no regrets.
“Governments and central banks,” he wrote, “could not have altered the course of the boom.”