One way to assess the significance of financial market turbulence is to look for political backlash. By that measure, the subprime mortgage debacle is still in its early stages. Yesterday's Senate hearing was largely limited to finger-pointing at regulators and lenders. But Christopher Dodd, the Senate banking committee chairman, warned darkly that as many as 2.2m people could lose their homes in the next few years.

Whether foreclosures on this scale will materialise remains anyone's guess. By historic standards, the recent rise in delinquency rates is serious, but not disastrous. But delinquency - borrowers failing to make their payments - is a backward-looking measure.