From his blog:

Two weekends ago the big news was the one-year anniversary of the Lehman Brothers bankruptcy and the ensuing panic. But when you look at the data, the real one-year anniversary of the panic is closer to now.

In the four weeks from Friday September 12, 2008, just before the Lehman bankruptcy, through Friday October 10, the S&P 500 fell by a huge 28 percent. But the decline was relatively modest (3 percent) in the first two weeks of that period, from September 12 to September 26, a year ago today. It is not unusual to see that size of change in a one or two week period. The real panic (the remaining 25 percent of that 28 percent decline in the S&P 500) occurred later, from September 26 to October 10. If you look at interest rate spreads or stock prices in other countries you see the same timing. Such facts have led me and others to be skeptical about the commonplace claim that it was simply the decision not to intervene and bail out Lehman’s creditors that triggered the panic. Rather I focus on the chaotic rollout of the TARP which began later and continued through October 13 when its ultimate use was finally defined.