In 2008, University of Chicago economist (and future Nobel laureate) Richard Thaler and Harvard law professor Cass Sunstein published their book Nudge, which popularised the idea that subtle design changes in the architecture of choice (“nudges”) can influence our behaviour. The book became a global phenomenon and marked an intellectual watershed. But 15 years after its publication, the question remains - has behavioural economics lived up to the hype?

Thaler and Sunstein based their thesis on the research and insights of psychologists Daniel Kahneman and Amos Tversky, which...