Central bankers are more cautious than the rest of us, but they are not immovable objects when confronted by irresistible force. Deterioriating economic prospects have spurred the Bank of England and the European Central Bank into action. Both can still do more.

Members of the Bank of England’s monetary policy committee had been dropping hints that a new round of quantitative easing – buying gilts with Bank money – was in the offing. As it was, they jumped the gun on markets, which expected the relaunch of QE in November. The ￡75bn magnitude of the purchase commitment was also heftier than many had dared to hope for.

Any enthusiasm should be kept in check. Doing something is a whole lot better than doing nothing, but ￡75bn will boost UK output by three-quarters of a per cent at most, on the Bank’s estimates. It could be much less: lower long-term interest rates benefit those with ample access to cheap credit already more than those whose spending is credit-constrained.