The usual response to the announcement of the Nobel memorial prize winner is “who?”. Not on Monday. Paul Krugman, a columnist for The New York Times, is (along with the late Milton Friedman) the most recognisable man ever to receive the honour. He was awarded his prize “for his analysis of trade patterns and location of economic activity”; he could with equal justice have been awarded it for reminding the world that rigorous economic ideas matter.

The award itself is no surprise: the Nobel has long seemed destined to land eventually in Mr Krugman’s lap. Yet eyebrows will be raised both by the timing and by the fact that Mr Krugman is the sole recipient of the award.