Post-war Hong Kong delivered one of the most dramatic improvements in living standards in history, a transformation regarded by Milton Friedman as an experiment in the potential impact of economic freedom on economic growth. This column assesses the contribution of one key official – finance minister Sir John Cowperthwaite – whose laissez-faire approach of ‘positive non-interventionism’, much admired by Friedman, underpinned that success. It also explores, 20 years on from the handover to China, whether a second stage of the Hong Kong economic experiment might be in progress, perhaps leading to faltering freedom and faltering growth.