RALEIGH – Having discussed the economics of health care and the reality of international cost comparisons in previous columns, let’s burrow down deeper into questions about health-care disparities. Here are two frequent assertions made by advocates of greater government intrusion into the medical marketplace, along with some antidotes to the contagion:

• America’s health care system consumes a much greater share of the GDP than do government-run systems in other countries. Yet measured by longevity and other statistics, Americans are no healthier. Surely this means that a single-payer system would save us money and at least not make us worse off health-wise, if not actually improving Americans’ health by wider access to care.

Most assuredly, this is not the proper conclusion. Beware of correlations masquerading as causalities. As the aforementioned John Goodman explained:

General life expectancy rates tell us almost nothing about the efficacy of health care systems, because, throughout the developed world, there is very little correlation between health care spending and general life expectancy – either among or within countries. While a good health care system may, by intervention, extend the life of a small percentage of a population, it has very little to do with the average life span of the whole population. In fact, the number of years a person will live is primarily a result of genetic and social factors, including lifestyle, environment and education.

Delving further into the statistics, one can find wide disparities in longevity among ethnic groups, within the U.S. and in other countries, too. If there is no attempt to correct for these difference characteristics, international comparisons are fraught with peril. Goodman provided the example of the Japanese, who are among the longest-lived groups on the planet not only in Japan but also in the U.S. – even though the two countries have rather-different health-care systems.

A more useful comparison of the marginal benefits of various kinds of health-care arrangements would be survivability after being diagnoses with an illness. That has a better chance of revealing the value of medical services, interventions, and technologies. American medicine does very well by this standard, offering among the lowest rates of mortality for women with breast cancer, men with prostate cancer, and infants born prematurely.

• Well, perhaps America does provide higher-quality medical services than are available elsewhere, but the fact that they are not universally available within our own country creates wide and unfair disparities in health.

There is more truth to this assertion, but it fails far short of explaining disparities of health outcomes among Americans of different backgrounds. A research team led by a Harvard University scholar has just released the results of a groundbreaking study that examines the potential causes of health disparities within the United States. Their fascinating finding is that differences in longevity cannot readily be explained by race, income, or access to health care. The kicker of USA Today’s coverage provides this summation by another scholar:

Jonathan Skinner of Dartmouth says much of the variation depends on such individual factors as diet, exercise and smoking, not health care. “Yet we spend much of our attention and 16% of our national income on health care,” Skinner says. “There’s no way that differences in the quality of health care can explain 20-year gaps in life expectancy.”

Now, to say that access to health care is not a decisive explanation of disparities is not to suggest that it plays no important role. Coming next, a discussion of America’s uninsured population, why lacking insurance is not the same as lacking care, and how public policy can best address this issue without sliding into coercive government control.

Hood is president of the John Locke Foundation.