Most of us, including many bankers, now agree that the last 25 years have been a dreadful mistake. Western consumers and businesses have too much private debt, with Japan serving as an awesome warning of how that can drag an economy down for decades.

There is a lot of hand-wringing over why regulation was so light-touch and why bankers were allowed to get away with so much. But those were the mistakes of a bygone world; the big question we face now is what to do next.

Last week, the governor-designate of the Bank of England, Mark Carney, and a man who was once a rival for the job, Adair Turner, both argued with one eye on Japan, where I have just spent an intriguing week, that it is time to open a debate about inflation. At the very least, declared Carney, we need to be very flexible about how inflation targets are met, keeping a weather eye on what is happening to growth and employment.