Previous research had suggested that lower-paying jobs were more likely to contribute to premature death. But the new research contends the real problem is a lack of education, which, in turn, virtually ensures a lower income.
The study, which appears in the Jan. 5 issue of the British Medical Journal, examined U.S. Census data for the years 1989-90. The 2000 Census reported that 84.1 percent of Americans who were 25 or older are high school graduates and 25.6 percent have graduated from college.
The study was done by Andreas Muller, a professor of health services administration at the University of Arkansas. He says his findings indicate that the level of formal education achieved is a more powerful predictor of mortality than differences in income.
"The higher the level of education, the better your chances for survival, the longer you live," he says.
But the reasons for that link aren't clear cut, Muller adds. He suspects, for example, that someone in a blue-collar job may not have access to health insurance or may be employed in a risky occupation. Other studies have suggested that lower-income people may not have access to adequate housing or police protection, he says.
At the other end of the socioeconomic scale, he says, "people who are well-educated tend to be in professional jobs, are not working outside, enjoy higher status, and health insurance coverage is not a main concern."
Muller also notes that health risk factors like smoking are more common among less-educated people.
The findings could point to a number of ways to improve mortality rates, he says.
"If you improve the social conditions of the folks who are living in poverty or in working-class or income-deprived conditions, this would help a lot," he says. Or, he says, giving people the chance to reach higher levels of education might improve their chances of landing a better paying job, leading to better health and a longer life.
George Davey Smith, the head of the epidemiology division at the University of Bristol in Great Britain, is familiar with Muller's study. He says some previous research had indicated that people's perception of their place in the social hierarchy influenced their health and mortality.
"This study suggests that that isn't the case," says Davey Smith, "that it actually isn't people's psychological reactions to things like inequality that are important.
"It's actually the conditions of life that are generated by economic conditions, which are reflected in factors like education, that are important," he adds.
Muller says his study looked at the issue at a single point in time, and he'd like to expand the study to include more recent census data.
What To Do
Visit the Stay-in-School Program from the U.S. Department of State.
For plenty of education statistics, check out the National Center for Education Statistics.
You can also read this article on reducing the dropout rate from the Northwest Regional Educational Laboratory.