by The Data Team
from The Economists
THE link between marriage and better health is well established. Less clear is whether marriage causes good health or vice versa—healthy people may simply be more likely to marry in the first place. In a recently updated paper Nezih Guner, Yuliya Kulikova and Joan Llull of Universitat Autònoma de Barcelona looked at data on Americans between the ages of 20 and 64 in order to try to work out which way the causation runs. Does marriage make people healthier?
They find that the gap in self-reported health between married people and singletons persists after controlling for things like income, age, and race; and that it increases over time, from three percentage points at younger ages to a peak of 12 percentage points between 55 and 59. (Cohabiting people are defined as singles in the study, but the researchers also tested what happened to the results when they were included with the married group. Answer: not much.) Next, they traced individuals’ health over time, in order to isolate how much of a person’s health is innate and permanent. That enabled the researchers to compensate for the fact that individuals with the physical and personality traits associated with good genes are more likely to marry in the first place. Once this measure is taken into account, the health gap between married people and singletons disappears at ages below 39. That suggests marriage is not having an effect on health when people are younger. Instead, causation runs the other way: the data suggest innate health drives up the probability of getting hitched.
But the picture is different for older people. There is still a six-percentage-point health gap between married and unmarried people between the ages of 55 and 59, a difference that cannot be explained by innate health. The researchers conclude that over time, marriage seems to be adding its very own dose of good health to a relationship, something they dub the “protective effect”.
How might this effect work? Insurance is one factor, at least in America: single people there are less likely to have health insurance than couples. But another factor may be behavioural. Marriage seems to encourage healthier behaviour: a single person is 13 percentage points more likely to give up smoking if he gets married than if he doesn’t. Married people are more likely than unmarried ones to have preventative health checks across a range of conditions—around 6% more likely to check their cholesterol or have a prostate or breast examination at the ages of 50-54, for example. So the next time your spouse nags you to go to the doctor, give thanks. Being married is good for your health.
In Britain there are three distinct models of family life (March 2013)
Most American women want their husband to have a steady job (Sept 2014)
How same-sex marriage swept across America (Oct 2014)