http://www.nber.org/papers/w8318.pdf

Explore the connection between income inequality and health in both poor and rich countries. Discuss a range of mechanisms, including nonlinear income effects, credit restrictions, nutritional traps, public goods provision, and relative deprivation. Review the evidence on the effects of income inequality on the rate of decline of mortality over time, on geographical patens of mortality, and on individual-level mortality. Much of the literature needs to be treated skeptically, if only because of the low quality of much of the data on income inequality. Although there are many puzzles that remain, the author conclude that there is no direct link from income inequality to ill health, individuals are no more likely to die if they live in more unequal places.