Uh, isn't this what Krugman and Stiglitz have been saying? It's why the two Nobel prize winners have been urging Obama to nationalize the banks:

WASHINGTON (Reuters) - Treasury secretary Timothy Geithner on Tuesday said difficulty in setting a value on banks' toxic assets was a continuing hindrance to their ability to lend and borrow.

In prepared testimony for delivery to the Congressional Oversight Panel that monitors Treasury's efforts to bail out troubled banks, Geithner said toxic assets were "congesting" the U.S. financial system and making it hard to get credit flowing normally again.

"Uncertainty about the value of legacy assets is constraining the ability of financial institutions to raise private capital," he said, adding that he hoped a public-private investment program will improve the ability to put a price on troubled mortgage and other assets.