Despite all the money going directly to the big banks, despite all the government guarantees and loans and special tax breaks, despite the shot-gun weddings and bank mergers, despite the willingness of the Treasury and the Fed to do almost whatever the banks have asked, the reality is that credit is not flowing.

Why? Because the underlying problem isn’t a liquidity problem. As I’ve noted elsewhere, the problem is that lenders and investors don’t trust they’ll get their money back because no one trusts that the numbers that purport to value securities are anything but wishful thinking. The trouble, in a nutshell, is that the financial entrepreneurship of recent years — the derivatives, credit default swaps, collateralized debt instruments, and so on — has undermined all notion of true value.

Many of these fancy instruments became popular over recent years precisely because they circumvented financial regulations, especially rules on banks’ capital adequacy. Big banks created all these off-balance-sheet vehicles because they allowed the big banks to carry less capital.