Can too many brainy people be a dangerous thing?

TEN YEARS ago Peter Turchin, a scientist at the University of Connecticut, made a startling prediction in Nature. “The next decade is likely to be a period of growing instability in the United States and western Europe,” he asserted, pointing in part to the “overproduction of young graduates with advanced degrees”. The subsequent surge in populism in Europe, the unexpected votes in 2016 for Brexit and then for President Donald Trump in America, and a wave of protests from the gilets jaunes to Black Lives Matter, has made Mr Turchin something of a celebrity in certain circles, and has piqued economists’ interest in the discipline of “cliodynamics”, which uses maths to model historical change. Mr Turchin’s emphasis on the “overproduction of elites” raises uncomfortable questions, but also offers useful policy lessons.

As far back as ancient Rome and imperial China, Mr Turchin shows, societies have veered from periods of political stability to instability, often at intervals of about 50 years. Consider America. Every pundit knows that Congress has become gridlocked, with Democrats and Republicans unwilling to compromise with each other. Fewer know that it was also highly polarised around 1900, before becoming more co-operative in the mid-20th century.