By the time the legislation had passed on Oct. 3, the global market crisis was so broad and so severe that we needed to move quickly and take powerful steps to stabilize our financial system and to get credit flowing again. Our initial intent was to strengthen the banking system by purchasing illiquid mortgages and mortgage-related securities. But the severity and magnitude of the situation had worsened to such an extent that an asset purchase program would not be effective enough, quickly enough. Therefore, exercising the authority granted by Congress in this legislation, we quickly deployed a $250 billion capital injection program, fully anticipating we would follow that with a program for buying troubled assets.

There is no playbook for responding to turmoil we have never faced…

A troubled-asset purchase program, to be effective, would require a huge commitment of money. In mid-September, before economic conditions worsened, $700 billion in troubled asset purchases would have had a significant impact. But half of that sum, in a worse economy, simply isn’t enough firepower.