The following originally appeared on The Upshot (copyright 2019, The New York Times Company).
Education is associated with better health outcomes, but trying to figure out whether it actually causes better health is tricky.
People with at least some college education have mortality rates (deaths per 1,000 individuals per year) less than half of those without any college education, according to the Centers for Disease Control and Prevention.
In addition, people who are more educated exhibit less anxiety and depression, have fewer functional limitations, and are less likely to have a serious health condition like diabetes, cardiovascular disease or asthma.
But causality runs both ways. People in poor health from a young age may be unable to pursue education as much as those with better health. On the other hand, a person who tends to focus on long-term outcomes may be motivated to develop healthier habits like regular exercise — even if blocked from a pursuit of higher education.
Some clever studies have teased out the causal effects of education by exploiting natural experiments. One, by the U.C.L.A economist Adriana Lleras-Muney, relied on state compulsory education laws enacted between 1915 and 1939. These laws required some children to obtain more education than they might have otherwise, resulting in longer lives for those that did so. According to the study, having an additional year of education by 1960 increased life expectancy at age 35 by 1.7 years.
Studies that relied on inducements for greater education because of a poor labor market or as a way to avoid the Vietnam draft found that increased education led to better health and a lower likelihood of smoking. This finding is one clue about how education may improve health. It can reduce people’s engagement in risky behaviors, perhaps because those behaviors could threaten the higher income that greater education typically confers.
But health behaviors can explain only a portion of the relationship between education and mortality. Education may also provide skills to analyze information and tackle complex problems — precisely what’s needed to navigate the modern health system and attend to chronic diseases.
A higher level of education is also associated with higher income and greater wealth, which are also correlated with better health.
Again, causality goes both ways. You have to be reasonably healthy to keep a job or to work long hours, for example. But higher income also often comes with better health insurance and easier access to health care.