‘For ten years or so, my name was “that jerk”,’ says Professor Richard Thaler, president of the American Economics Association and principal architect of the behavioural economics movement. ‘But that was a promotion. Before, I was “Who’s he?”’

Thaler has had to get used to putting noses out of joint. His academic research, initially controversial, sparked an entirely new branch of economics, and now governments are adopting his theories across the globe.