The American medical system has the latest technology, the greatest variety of new drugs and unparalleled resources. But anyone who thinks we're getting something great for our dollars inevitably encounters a two-word rebuke: infant mortality.

The United States is the richest nation on Earth, but it comes in 29th in the world in survival rates among babies. This mediocre ranking is supposed to make an irrefutable case for health care reform. If we cared enough to insure everyone, we are told, we would soon rise to the health standards of other modern nations. It's just a matter of getting over our weird resistance to a bigger government role in medical care.

But not every health issue is a health care issue. The reason boxers are unusually prone to concussions is not that they lack medical insurance. Doctors may treat head injuries, but it's a lot easier to prevent them. Absent prevention, we shouldn't blame the medical industry for punch-drunk fighters.

Like life expectancy (the subject of a previous column), infant mortality is a function of many factors. The more you look at the problem, the less it seems to be correctable by a big new federal role in medical insurance -- and, in fact, the less it seems to be mainly a medical issue at all.

No one denies the problem. Our infant mortality rate is double that of Japan or Sweden. But we live different lives, on average, than people in those places. We suffer more obesity (about 10 times as much as the Japanese), and we have more births to teenagers (seven times more than the Swedes). Nearly 40 percent of American babies are born to unwed mothers.

Factors like these are linked to low birth weight in babies, which is a dangerous thing. In a 2007 study for the National Bureau of Economic Research, economists June O'Neill and Dave O'Neill noted that "a multitude of behaviors unrelated to the health care system such as substance abuse, smoking and obesity" are connected "to the low birth weight and preterm births that underlie the infant death syndrome."

Nicholas Eberstadt, a scholar at the American Enterprise Institute in Washington, also attributes the gap largely to conduct. Comparing white Americans to Norwegians in his 1995 book, "The Tyranny of Numbers," Eberstadt concluded that "white America's higher rates of infant mortality are explained not by poverty (as conventionally construed) or by medical care but rather by the habits, actions and indeed lifestyles of a critical portion of its parents." Whites are not unique in those types of behavior.

African-American babies are far more likely to die than white ones, which is often taken as evidence that poverty and lack of health insurance are to blame. That's entirely plausible until you notice another racial/ethnic gap: Hispanics of Mexican or Central or South American ancestry not only do consistently better than blacks on infant mortality, they do better than whites. Social disadvantage doesn't explain very much.

Nor does access to prenatal care, as the health care critique implies. It used to be assumed that if you assured that pregnant low-income women could see a physician, their infants would do much better. Not necessarily. When New York expanded access to prenatal care under Medicaid, the effort reduced the rate of low birth weight infants by just 1 percent. In Tennessee, after a similar effort, researchers found "no concomitant improvements in use of early prenatal care, birth weight or neonatal mortality." So why does our infant mortality rate exceed that of, say, Canada, where health care is free at the point of service? One reason is that we have a lot more tiny newborns. But underweight babies don't fare worse here than in Canada -- quite the contrary. The NBER paper points out that among the smallest infants, survival rates are better on this side of the border. What that suggests is that if we lived under the Canadian health care system, we would not have a lower rate of infant mortality. We would have a higher one. A lot of things could be done to keep babies from dying in this country. But the health care "reform" being pushed in Washington is not one of them.