But, as a sign of what may lie ahead, Mr Solnik has spotted an increase in the correlation of stockmarkets within regions, notably Asia and continental Europe, since the 1960s.

ECONOMIST: All fall down

The occasional crash aside, there has been no great increase in correlation between stockmarkets in different countries for several decades, according to Bruno Solnik, an economist at the Haute Ecole de Commerce in Paris.

ECONOMIST: All fall down | The