A year ago today, the venerable investment-banking firm Lehman Brothers filed for bankruptcy protection after the Federal Reserve and the Treasury Department pointedly refused to bail the company out, and no other Wall Street outfit was willing to step into the breach. It was the largest bankruptcy ever in the U.S., but the really big news was what happened afterward. First came a financial panic that threatened to shatter the global capitalist order, then came an unprecedented, and unprecedentedly expensive, effort by governments on both sides of the Atlantic to patch things up.

You already knew all this, of course. It happened just last year, and in recent days the news media have engaged in an orgy of commemoration and explanation of the Lehman collapse and its aftermath. So here’s the $64 trillion question: What, if anything, have we learned from the experience? (See the top 10 financial collapses of 2008.)