The equality-health question, explored in numerous studies, strikes at the heart of the health care reform debate: the system is a microcosm of how resources and well-being are distributed throughout society. Reform efforts must wrestle with the issue of whether the private market can really sustain people's health when so much of health is bound up in the overarching social structure.

In a National Bureau of Economic Research analysis published in 2003, researcher Angus Deaton found a complex connection between mortality and inequality. The exact casual chain is unclear, but the fascinating thing is how race stands out as a unique determinant:

In both the state and the city data, mortality is positively and significantly correlated with almost any measure of income inequality. Because whites have higher incomes and lower mortality rates than blacks, places where the population has a large fraction of blacks are also places where both mortality and income inequality are relatively high. However, the relationship is robust to controlling for average income (or poverty rates) and also holds, albeit less strongly, for black and white mortality separately. Nevertheless, it turns out that race is indeed the crucial omitted variable. In states, cities, and counties with a higher fraction of African-Americans, white incomes are higher and black incomes are lower, so that income inequality (through its interracial component) is higher in places with a high fraction black. It is also true that both white and black mortality rates are higher in places with a higher fraction black and that, once we control for the fraction black, income inequality has no effect on mortality rates.... None of this tells us why the correlation exists, and what it is about cities with substantial black populations that causes both whites and blacks to die sooner.

But Deaton adds that other kinds of inequality may be bigger factors, citing studies in which apparent impacts of socioeconomic inequality "vanish once we control for racial composition. I suggest that inequality may indeed be important for health, but that income inequality is less important than other dimensions, such as political or gender inequality."

Such studies seem to confirm what we can easily intuit from looking around our neighborhoods: the toxic intersection of the color line, class divides, and health barriers. For disadvantaged individuals as well as the social system that has failed them, the synergy of racial and socioeconomic inequities could prove deadly.

Image: Emergency room at a hospital in Madera, CA. (Gary Kazanjian / AP)