The UK is in recession. The estimate of a decline of 0.5 per cent in the third quarter, after stagnation in the second quarter, ends the debate. This is the beginning of a lengthy and, quite possibly, deep recession. How long and how deep? The answer depends on what the authorities do.

This is the moment at which David Blanchflower, an external member of the monetary policy committee and professor of economics at Dartmouth College in the US, is entitled to say “I told you so”. Prof Blanchflower has voted for a cut on every occasion since October 2007. In retrospect, he was right to push strongly in this direction, usually against majority opinion on the MPC. His views on the economy deserve respect now.