Better-educated Americans increasingly live longer than everyone else, and children from higher-income families in the United States are getting more education than other people.
These are two of the most disturbing trends in the U.S., and it's entirely plausible that they are related.
Economists have recognized many possible connections between health and education, but so far they have done little to link the trends toward greater inequality in each area.
Linkages could run in either direction: Disproportionate gains in income among affluent families may facilitate college completion by their children, and also provide resources that lengthen their life expectancy.
On the other hand, something such as better access to cutting-edge medical treatments could increase life expectancy disproportionately for children from high-income families. And that, in turn, may make them more likely to complete college -- since the payoff from a college degree would be enjoyed over a longer period of time. In that case, a force that increases life expectancy for higher-income families would also widen the college-completion gap.
Some evidence suggests that college decisions are surprisingly responsive to life expectancy. One recent study looked at what happens when people learn that they have Huntington's disease. Huntington's is caused by an inherited genetic mutation, and any child of an afflicted person has a 50 percent chance of developing the disease, which shortens life expectancy to about 60 years.
The researchers -- economist Emily Oster of the University of Chicago and neurologists Ira Shoulson of Georgetown University and Ray Dorsey of Johns Hopkins University -- found that offspring who learned they had the Huntington's disease gene were 30 percentage points less likely to complete college than those who didn't have it.
What's more, those people who were not genetically tested but began showing symptoms of the illness before age 18 were much less likely to complete a degree than those whose symptoms became apparent after the traditional age of going to college.
These findings are in line with those from studies in other countries, and they may help solve a puzzle about the widening college-completion gap by family income.
As I noted in a previous column, the gap has occurred disproportionately among daughters, rather than sons, of high-income families, so it's not a simple matter of wealthy families directly or indirectly buying advantages for their children. If that were true, why wouldn't family money help sons as much as daughters?
But consider this fact: The gain in life expectancy at age 25 for non-Hispanic white female college graduates compared with that for less-educated women has been much more rapid than that for non-Hispanic white males. From 1990 to 2008, the gap between the female college graduates and high-school dropouts widened by a factor of five, while the gap for males increased by a factor of about 2.6. (The life-expectancy gradient remains steeper for men, but the female gradient has been steepening more quickly and is rapidly catching up to the male one.)
The differential gains in life expectancy may be due to something inherent in education or to something else that may be lengthening the lives of high-income women, thereby increasing the incentives for them (relative to high-income men) to complete college.
The linkages between the widening gaps in life expectancy and college completion aren't yet sorted out. What's clear, though, is that both trends deserve more attention -- and they should be examined together.
Peter Orszag is vice chairman of corporate and investment banking and chairman of the financial strategy and solutions group at Citigroup and a former director of the Office of Management and Budget in the Obama administration.