The Troubled Asset Relief Programme is certainly troubled. A plan to buy up $700bn of mortgage-backed securities turned into a scheme primarily aimed at recapitalising banks and supporting commercial paper markets. Now, with more money on hand than expected, every major vested interest in the US is trying to secure Tarp support. It may have been created only last month, but policymakers must remember what it is for.

The mechanism by which the Tarp would work was never clear. The objective of the Tarp, however, was. Although the Treasury secretary, Hank Paulson, has suffered regular Damascene conversions on what exactly he wanted to do with his $700bn, it was always intended to hold the financial sector together in order to support the real economy and prevent a downturn becoming a depression.