A recent Unicef report ranked the wellbeing of children in 21 rich countries.1 The report aggregated national data on more than 40 indicators from credible sources in six dimensions—material wellbeing (related to income, poverty, material goods), health and safety, educational wellbeing, family and peer relationships, behaviours and risks, and subjective wellbeing (how the child sees his or her self). The press had a field day when the report was published,2 because the United States and the United Kingdom were in the bottom five countries for five of the dimensions. The UK ranked 12th in health and the US ranked 12th in education; questions were rightly asked about how this could happen and what the government was going to do about it.

In this week's BMJ, Pickett and Wilkinson3 attempt to explain the results of the Unicef report by combining the measures of wellbeing of children with national data on income. They selected three measures of income—income inequality (ratio of the top fifth of incomes to the lowest fifth); relative child poverty (the proportion of children living in households in which …