For a very pleasant change, this week’s data on US housing is ground for some relief. The supply of unsold houses is reducing, sales have stopped falling and prices are falling less swiftly than they had been.

As far as they go, all of these factors are positive. House prices are crucial to the fate of the dubious collateral held by financial institutions which has driven the credit crisis. If prices recover, defaults should be lower, and the ultimate damage to mortgage-related securities should be less.