It is easy to mock economic theory. Any fool can see that the world of neoclassical economics, which dominates the academic field today, is a gross caricature in which every trader or company acts in the same self-interested way – rational, cool, omniscient. The theory has not foreseen a single stock market crash and has evidently failed to make the world any fairer or more pleasant.

The usual defence is that you have to start somewhere. But mainstream economists no longer consider their core theory to be a “start”. The tenets are so firmly embedded that economists who think it is time to move beyond them are cold-shouldered. It is a rigid dogma. To challenge these ideas is to invite blank stares of incomprehension – you might as well be telling a physicist that gravity does not exist.