There is no pathway by which income inequality affects health (but
somehow it does?)
There is a seemingly robust negative association between the level of
income inequality of a population and its health outcomes. Yet there has
been little investigation of any of the theorized mechanisms for why
this is the case. Using hierarchical models of individuals nested within
states, I find no evidence that income inequality affects health due to
relative material deprivation, nor adverse psycho-social effects on the
badly-off. Nor do I find support for the contention that the social
disintegration caused by inequality mediates the association. I find no
evidence either that racial composition has effects on health via social
cohesion. This places the burden of proof on the shoulders of the
defenders of the `income inequality hypothesis' to demonstrate causation
or consider other channels by which inequality might make its effect, to
counter the charge that the association is spurious.