There is a long-standing debate about whether the middle-income US employee has suffered a fall in living standards or merely achieved modest gains. At best he has had a meagre share of the rise in the US national income, not merely under President George W. Bush but in the past 40 years.

On February 10, I summarised a paper by a leading US authority, Robert J. Gordon, who concluded that the pressures on the ordinary citizen came from an enormous increase in the share of the top 10 per cent of earners in the national pay bill. I would hesitate to take issue with Professor Gordon’s numbers; but even the best of econometric studies is inevitably backward looking. There is surely a case for a more speculative discussion of what may lie ahead.