Poverty, Income Inequality and Health

That there is a correlation between poverty and a higher risk of a disease and shorter life span is well known However, an examination of several different studies (subscription required) in the December Scientific American leads these researchers to conclude that psychosocial stresses associated with poverty may increase the risks of many illnesses.

When you examine socioeconomic status (SES), a composite measure that includes income, occupation, education and housing conditions, it becomes clear that , starting with the wealthiest stratum of society, every step downward in SES correlates with poorer health.

Researchers have long known that people with low socioeconomic status (SES) have dramatically higher disease risks and shorter life spans than do people in the wealthier strata of society. The conventional explanations-that the poor have less access to health care and a greater incidence of harmful lifestyles such as smoking and obesity-cannout account for the huge discrepancy in health outcomes.

It's a common presumption that since for the poor health care is less easily accessible and of lower quality, this alone can explain the differences in health between them and the well-off. But the authors of the article point to a decades-long series of studies in the UK which show otherwise. The British researchers targeted civil servants at different ends of the spectrum and found that despite the fact that all the employees had access to the UK's universal health care system, those on the lower end (messengers and porters) have "far higher mortality rates from chronic heart disease than administators and professionals do." Other studies also show that the SES "gradiant" (the difference in quality of health between the poorest and the wealthiest) exists even for diseases for which health care access is irrelevant: "No amount of medical checkups, blood tests and scans will change the likelihood of someone getting type 1 (juvenile-onset) diabetes or rheumatoid arthritis, yet both conditions are more common among the poor."

An unhealthy lifestyle is also unable to entirely explain the difference. The UK studies, controlling for such factors as smoking and level of exercise, were still able to only account for about 1/3 of the SES gradient, leaving a full 2/3 of the difference to be explained by something other then unequal access to health care and different lifestyles.

The authors state that the differences can be explained only by taking into account what they call the "psychosocial consequnces of SES", or in other words the stressful effects of being poor, and the long-term consequences of those effects. The authors postulate that the chronic stress of being poor is the only way to account for the otherwise unexplainable differences in quality of health between the well-off and the poor:

An extensive biomedical literature has established that individuals are more likely to activiate a stress response and are more at risk for a stress-sensitive disease if they (a) feel as if they minimal control over stressors, (b) feel as if they have no predictive information about the duration and intensity of the stressor, (c) have few outlets for the frustration caused by the stressor, (d) interpret the stressor as evidence of circumstances worsening, and (e) lack social support for the duress cuased by the stressors.

These factors apply to stress in general, but it is easy to overlay this structure on a person living in poverty, and see how they correlate nearly exactly the circumstances they find themselves living in; little control over their economic situation, no way to know if or when their poverty will end, no means to take their poverty off their mind, feeling in general that their situation can only worsen and lacking family or societal networks to provide for any means to alleviate their conditions of living or their poverty.

Their conjecture is not so surprising. The authors are careful to explain the well-documented deleterious effects of long-term stress in general on the body, and there's no doubt that living in poverty is more stressful then living well or living wealthy. What is surprising is that more than the subjective condition of poverty is at work here; in fact, people are worse off when the feel poor:

This same point emerges from comparisons of the SES/health gradient among nations. A relatively poor person in the U.S. may objectively have more financial resources to purchase health care and protective factors than a relatively wealthy person in a less developed country yet, on average, will still have shorter life expectancy (italics mine.)

And the yet the SES gradient is not the only explanation for the difference in the quality of healthy between the poor and the wealthy:

Over the past 15 years [Richard Wilkinson of the University of Nottingham] have reported that the extent of income inequality in a community is even more predictive than SES for an array of health measures. In other words, absolute levels of income aside, greater disparities in income between the poorest and the wealthiest in a community predict worse average national health. Wilkinson has shown…that decreased income inequality predicts better health for both the poor and the wealthy.

Put more simply, SES explains the difference in quality of health between the poor and the wealthy in any society, but the quality of health is lower in societies in which there are larger gaps between the poor and the wealthy. What explains this phenomenon?

Wilkinson and other in the field have long argued that more unequal income in a community is, the more psychosocial stress there will be for the poor. Higher income inequality intensifies a community’s hierarchy and makes social support less available...Moreover, having your nose rubbed in your poverty is likely to lessen your sense of control in life, to aggravate the frustrations of poverty and to intensify the sense of life worsening.

Wilkinson’s income inequality work suggests that the surest way to feel more is to be made to feel poor-to be endlessly made aware of the haves when you are a have-not.

Unfortunately, other studies show that income inequality not only influences public health, but helps to perpetuate a lower quality of public health:

John W. Lynch and George A. Kaplan of the University of Michigan at Ann Arbor have recently proposed another way that people are made to feel poor. Their "neomaterialist" interpretation of the income inequality phenomenon…runs as follows. Spending money on public goods (better public transit, universal health care and so on) is a way to improve the quality of life for the average person. But by definition, the bigger the income inequality in a society, the greater the financial distance between the average and the wealthy. The bigger this distance, the less the wealthy have to gain from expenditures on the public good. Instead they would benefit more from keeping their tax money to spend on their private good. So, the more unequal the income is in a community, the more incentive the wealthy will have to oppose public expenditures benefiting the health of the community.

In other words, as the well-off become wealthier, they have more income to spend on health care and so benefit less from publicly available health care. As they benefit less, they seek to spend less on public health care. As they spend less on public health care, decreased average public health results. And as there is a very clear reciprocal relationship between health and economic opportunity (as in those who are in poor health are less able to work and vice versa) it becomes clear that as far as public health is concerned, income inequality perpetuates itself.

What these numerous studies show us then is that while universal health care would do much to reduce the low quality of public health in our country, continuing differences in income in our country and the vast and ever-growing income inequality will act significantly to prevent the poor from enjoying even close to the advantages in health that the wealthy enjoy. And while the idea of universal health care in our country is slowly gaining traction, it is much less likely that we'll be able to do anything about income ineqaulity anytime soon.