From Mr Jack Tatom.

Sir, What a contrast to have Jeff Diermeier's clear explanation of the critical importance of mark to market accounting (Letters, March 20) on the same day as Paul de Grauwe's endorsement of temporarily suspending it ("Act now to stop the market's vicious cycle"). Marking asset values to the market prices is most useful and relevant when a firm has a significant chance of having to sell assets, such as when funding becomes expensive, or when it nears bankruptcy. These are precisely the circumstances in which some financial services firms now find themselves.