Here is an interesting quote:
Ben Shalom Bernanke was raised a druggist’s son in Dillon, South Carolina, a city (today) of 6,800. He studied the Depression as a graduate student at MIT, and as a young academic earned his reputation by expanding on Milton Friedman’s classic monetary history. According to Friedman, the Fed’s failure in the 1930s was a matter of not printing enough money. Bernanke deduced that the real failure was letting the banking system implode. “What Bernanke discovered was that it wasn’t the quantity of money, it was that the banks stopped lending,” says Stanley Fischer, formerly Bernanke’s thesis adviser at MIT and currently the governor of the Bank of Israel. “More than the decline in money, it was the collapse of credit.” The implication was that regulating banks in good times—and, if need be, rescuing them in bad—was of prime importance, something Bernanke would remember in the 2007–09 crisis.
When will economists recognize that Friedman was right and Bernanke was wrong? Or rather, the problem is the growth path of Nominal GDP, and bailing out the banks while letting nominal GDP fall to a lower growth path doesn't fix the problem.