Anthony Atkinson is often considered the father of modern inequality research. He devoted his academic career to developing methodological tools and policies proposals with the aim of increasing people’s wellbeing. In this obituary it is argued that his contribution to the discipline of economics rests on three major and interrelated themes: measurement, distribution and welfare. Taking note of Atkinson’s innovative contribution to the field, a parallel with William Petty, the founder of political arithmetic, is drawn. 

JEL Classifications: B32, D63, H10.