The Public's Health: Income Inequality and Our Health | Public Health Post

Pre-tax incomes for the poorest 50 percent of Americans have stayed mostly unchanged for the past 40 years. As our economy has grown, the pre-tax share of national income among the poor has dropped significantly, widening income gaps in the country. We leave the question of why inequality matters for the economy to others. What is of concern to us is whether income inequality matters to our health and to the extent that it does, how we in the health profession should respond. 
Twenty-five years ago, Richard Wilkinson, then a professor at the University of Sussex, published a paper in the British Medical Journal called “Income distribution and life expectancy.” The paper concerned twelve European countries and concluded that “the relation between income distribution and life expectancy is sufficiently strong to produce significant associations.” The paper’s provocative thesis launched two decades of intense scientific discussion about the role of national income inequality in producing health (and death), including several systematic reviews, and books. This work, which continues to the present day, shows that income inequality is a foundational driver of physical and mental health. By way of example, a systematic reviewpublished just this February considers the relationship between income inequality and depression and concludes that across studies there is “greater risk of depression in populations with higher income inequality relative to populations with lower inequality.”
Why might income inequality affect the health of the public? 
Countries or regions where there are wide gaps in income are characterized by weaker social ties and less investment in the social and physical resources that create health. Countries with more income inequality are less likely to have healthy air, water, food, safe places to work and play, and affordable quality housing—all of which create health.
We are convinced then that income inequality should indeed be the remit of public health professionals. Embracing this, the authors of the systematic review of depression conclude that “policy makers should actively promote actions to reduce income inequality, such as progressive taxation policies and a basic universal income. Mental health professionals should champion such policies.”
Does entering the conversation on taxation policies, the minimum wage, and universal income guarantees stretch the bounds of what most of us expect to be the topics of public health? 
Unquestionably it does. But we believe that such stretches should be our new purview. After all, as recently as eighty years ago few imagined that cigarettes had anything to do with health, and doctors promoted cigarettes. It was a stretch of our collective imagination then to see health tackling smoking and the tobacco industry, as much as it is now to see addressing income inequality as part of our work. But the evidence suggests that they both matter to our public health. With the responsibility of witnesses, we should speak up, with a careful eye on new data and humility about which policies to “champion” when considering large issues like income inequality.

Michael Stein & Sandro Galea