That leaves America today with many workers consigned to low-productivity, low-wage jobs, but growing shortages in key areas of skills. Machine operators in modern factories require at least basic programming knowledge, and the greatest risk to manufacturing industry is the absence of qualified workers. With long-term idleness comes degradation of skills. American workers are not only excluded from the benefits of the modern economy, but to an increasing extent are unqualified for the modern economy. It is into this thicket that the new president must wade. Trump has said that he wants to spend $1 trillion on infrastructure, which is in urgent need of upgrades. The stock market takes him at his word, and the stock of construction equipment manufacturers has soared since his election. Here Trump is magnificently right, as Keynes said of Roosevelt in another context. Repairing ageing infrastructure is a basic economic requirement, but it also allows many less-skilled workers to re-enter the labour force after a long and unwanted furlough. More threatening to America’s long-term economic prospects than deteriorating capital stock is the extended idleness of a large proportion of her working-age men.

The Obama recovery of 2009-2016 was the weakest on record; had the recovery achieved the same growth rates as in past recoveries, America’s economy would be about 10 per cent larger than it is today. Not only the pace of growth but its composition gives cause for concern. In America’s dynamic economy of the past, start-ups contributed more than 100 per cent of employment, which is to say that established businesses shed jobs while new businesses more than replaced them. After 2008, though, the contribution of start-ups to employment growth has been close to zero (the reported increase in employment of the largest 1,500 American companies by stock market capitalisation is roughly equal to total employment growth from 2009 to 2015).

The American economy lost its entrepreneurial character under the Obama administration. The academics will take some years to chew over the data, but a reasonable conjecture is that more restrictive credit standards after 2008 and a much higher regulatory burden dampened the animal spirits of American entrepreneurs. The Affordable Care Act, moreover, imposed substantial costs on businesses with more than 55 employees, which may explain why many businesses failed to grow. Large companies employ small armies of lawyers and lobbyists to handle regulatory issues which may prove overwhelming to start-ups. The clubby collaboration between corporate giants and the Obama administration stood in sad contrast to the paralysis of the entrepreneurial sector. Trump’s claim that the system was “rigged” was an exaggeration, but the system was skewed to the advantage of entrenched companies to an extent not seen since the 1960s.