Income inequality and health: pathways and mechanisms.

The relationship between income and health is well established: the higher an individual's income, the better his or her health. However, recent research suggests that health may also be affected by the distribution of income within society. We outline the potential mechanisms underlying the so-called relative income hypothesis, which predicts that an individual's health status is better in societies with a more equal distribution of incomes. The effects of income inequality on health may be mediated by underinvestment in social goods, such as public education and health care; disruption of social cohesion and the erosion of social capital; and the harmful psychosocial effects of invidious social comparisons.