Mr Bernanke delivered a celebrated speech on the topic in November 2002, when still a governor.* He spoke quite soon after the US stock market bubble burst in 2000. Policymakers then feared the US might soon follow Japan into deflation – sustained declines in the general price level.

Yet Mr Bernanke then insisted “that the chance of significant deflation in the US in the foreseeable future is extremely small”. He pointed to “the strength of our financial system: despite the adverse shocks of the past year, our banking system remains healthy and well-regulated, and firm and household balance sheets are for the most part in good shape”. The words “pride” and “fall” come to mind. Six years and a housing-cum- credit bubble later, chairman Bernanke must be sadder and wiser.

Mr Bernanke's view was also that “the best way to get out of trouble is not to get into it in the first place”. The fear that reversing deflationary expectations would prove hard explains why the Fed has cut its official interest rate so quickly since the crisis broke in August 2007.