News Blog readers who enjoyed my analysis of Chetty’s monumental JAMA article on income and longevity at age 40  may wish to read a commentary by last year’s Nobel prize winner for economics, Angus Deaton. Some points:
- Studies correlating income with longevity over-estimate the association between wealth and age because they assume that people to whom the results are extrapolated will remain in their income groups.
- The association between wealth and health overestimates the causal effect of wealth on health because health also influences wealth to a degree.
- While the life expectancy of poor people varies widely by locality, those of rich people does not.
- Given the poor health of middle-aged Americans, especially white Americans from low socio-economic levels, we can expect to see health disparities of adults widen in the short-term. Health disparities in children in America are declining (see previous post).
- In setting policy – especially tax rates – be guided by absolute not relative income disparities. Every society has a top and bottom percentile and always will have; just like more than half of people cannot be above median.
- Be careful when someone tells you that health disparities are growing – often (as now) relative disparities widen as absolute disparities decline. This can happen because the same relative risk reduction has a bigger (absolute) effect when baseline rates of ill-health are high (as among poor people) than when they are low (as among the financially better-off).
- Education and cognitive ability are independent predictors of both health and wealth. Since parents are important educators, the regress is hard to break.
— Richard Lilford, CLAHRC WM Director
- Chetty R, Stepner M, Abraham S, et al. The Association Between Income and Life Expectancy in the United States, 2001-2014.JAMA. 2016; 315(6):1750-66.
- Deaton A. On Death and Money. History, Facts, and Explanations. JAMA. 2016; 315(16): 1703-5.