One of the great mysteries of Japan’s economy during the 2010s decade of “Abenomics” stimulus was why the rapid ageing of the population did not drive up wages for those of working age. With almost a third of the population aged 65 or above, went the theory, pensioners would surely start to run down their assets, first through spending on fancy meals out and trips to the golf course, then ultimately to pay for care as their health began to fail.

Such spending would translate into demand for the labour of a shrinking pool of younger workers. That would in turn push up wages across the board, and then these rising wages would drive up prices and help the Bank of Japan in its dogged attempt to reach a 2 per cent inflation target after years of trying.

The underlying idea — that population ageing reaches a point where saving for retirement tips over into increased spending and demand for labour — is central to the argument made by economists Charles Goodhart and Manoj Pradhan. They propose that a demographic reversal will turn the current era of stagnant prices into a new age of inflation.