The Obama administration is thinking of taxing banks according to the size of their liabilities, according to media reports. The new tax would aim to recoup the cost of the bailout and, according to some reports, might reach $120 billion.

A liability levy is one of several options being floated. Another is a windfall tax on bank profits. The administration appears not to be keen on either a tax on financial transactions -- a so-called Tobin tax -- or a tax on bankers' bonuses.