Philip Ball’s recent article on mainstream economics has attracted strong criticism on the letters page. Mr Ball argues that the subject relies on the rational, omniscient decision-maker. Further, it has mistakenly placed an idea from physics – that of thermodynamic equilibrium – at the core of its theory.

His critics claim that this is a caricature of the subject. Substantial advances have been made, they say, particularly in the last 10 to 15 years.