This economic divide has not gone unnoticed by public health researchers, who have produced a substantial literature documenting and discussing the links between increasing economic inequality and poorer health. The analyses of Wolfson et al. We would observe that one area had more wealthy people than the other and could attribute any aggregate differences in health between the areas to their compositional differences, but in reality it may be more difficult to separate individual and area characteristics. If such an argument is extended to the forces that determine the distribution of economic opportunities with and between areas, it is easy to see how clarifying the separate roles of individual economic status and income inequality becomes difficult. Multilevel models do allow us to examine the question of which subpopulations show an effect of income inequality on health.
Many hypotheses are possible.
For example, one could argue that we should only expect those who are most marginalized and vulnerable to suffer. Although it is still too early to come to a definitive conclusion, the general pattern of results is not consistent with the latter scenario. Thus, Lochner et al. 8 found significant results primarily for near-poor Whites, Daly et al. The policies that result in high levels of income inequality also are associated with systematic underinvestment across wide ranges of human, physical, social, and health infrastructure. In the US, higher income inequality is significantly associated with many aspects of infrastructure, unemployment, health insurance, social welfare, work disability, educational and medical expenditure, and even library books per capita.