Under the terms of the plan, announced in September, Ireland will pay €54bn to take over bank debt with a book value of €77bn. The initiative is intended primarily to free the banks of their toxic asset burden and encourage lending to small businesses, according to finance minister Brian Lenihan.

But contrary to initial appearances, banks won't be taking a haircut on the assets so much as they will be  getting something of a hair transplant, as one person familiar with the plan put it.

Consider this:  Nama will issue the banks with bonds and subordinated debt to the value of €54bn to take over both performing and distressed loans, many of which were made to the country's largest property developers and collateralised by what one person described as a "rag bag mix of property,  including fields in the middle of nowhere that don't stand a chance of being developed".

The book value of these loans may be €77bn, but as of  September and according to comments by Lenihan, the market value of the portfolios was closer to €47bn.

So you can look at Nama in either of two ways. On the one hand, the banks involved will be taking a haircut of around 30 per cent on the book value of the loans. On the other, the government is paying the banks a premium of about 13 per cent versus the September value of the loans.