A constantly growing literature shows the powerful effect that inequality has on people’s health. However there’s less information on when in someone’s life inequality is most harmful. A new study looking at the health of people who grow up in the US seeks to fill that gap.

This new study finds that people who grew up at a time when inequality was lower are healthier in later life than people who grew up when inequality was higher. The findings suggest that living in a country with a high level of inequality in the first five years of your life could be permanently damaging your health.

There are several ways in which inequality at an early age could be damaging health in later life.  One possible reason is that lower inequality is associated with provision of public goods like immunisations, especially to poorer citizens, which improve health in later life.  Another possible reason is that inequality causes children’s parents to become stressed which harms the child’s wellbeing and hampers a child’s development. This fits with existing research showing that greater inequality is linked to lower child wellbeing and that parental financial stress may damage children’s educational outcomes.

There are some issues with the study which suggest we should be cautious in how enthusiastically we champion their findings. Inequality is measured using top income shares from income tax records and as the researchers admit, this source is imperfect as it misses out large chunks of the population who aren’t in tax records. However this data allows them to go further back in time than other more commonly used measures. Additionally they use information on self-reported health rather than objective measures of health, so they may be finding that inequality affects people’s perceptions of their health rather than their actual health. The study is also only measuring the effects of inequality over time. There are probably other effects that happen at the same time as inequality rising which affect health and which are difficult to control for, like changes in medical technology.  

The authors’ conclusion presents a very good summary of what the paper shows and what we can conclude from the literature: “While it is premature to conclude that exposure to early life income inequality causes worse health in later-life, our results suggest that, at least in the U.S., they are statistically linked.” We hope to see further research in this area that helps increase our understanding of how and when inequality harms people.

This paper adds to the mountains of literature showing that inequality harms us all. We may be permanently damaging our children’s health with our country’s dangerously high inequality. This provides yet another reason for us to urgently tackle inequality before we harm yet more people.

Tim Stacey, Senior Policy and Research Advisor