If markets are the solution to all problems, why does no-one rely on them in a pandemic? It is common for anyone who suggests a measure to fight poverty or global warming to be assailed by “market fundamentalism”, the belief that markets cure all social and economic ills. Any change that prevents markets from working the way economic theories say they do is, we are told, harmful.

This is the message we hear most often in discussions on the economy (broadcasters here seem to believe that “economist” is another word for market fundamentalist). It has guided the policies of the powerful for decades, often imposing huge hardship on poor countries. And yet the last few weeks have shown that no-one but a small core of zealots really believes in it...