Across America, people are falling ill and dying young.

These men and women have something in common. In fact, they stand out because of something they don’t have: a college degree.

A recent report, by the Princeton University economists Anne Case and Angus Deaton, made the stakes clear: Men and women who haven’t been to college live shorter, less healthy lives, and are losing ground compared with college graduates.

Read the full story: Across America, there’s a new public-health crisis — the lack of a college degree.

This is about more than money — the findings suggest that pain, stress, and social dysfunction may all play a role. Here’s what you need to know about the research.

Ms. Case and Mr. Deaton found that less-educated Americans were dying younger. Is that really so striking?

In a word, yes. For decades, life expectancy for Americans has been improving, thanks to advancements in technology and medical care. Before 1999, middle-age mortality rates were declining by about 2 percent a year. But suddenly, starting in the late 1990s, rates of morbidity and mortality — in other words, of sickness and death — began to increase for white men and women between the ages of 45 and 54 who did not have a college degree.

Since then those rates have been climbing by about half a percentage point a year among the white working class. “In this historical context of almost continuous improvement,” write Ms. Case and Mr. Deaton, “the rise in mortality in midlife is an extraordinary and unanticipated event.”

The researchers originally noticed rising death rates among the middle-aged and now see a similar deterioration for less-educated adults of all ages. The one exception is the elderly.

At the same time, however, longevity has continued to improve for people who hold college degrees. The resulting disparity is striking: The mortality rate for 50- to 54-year-old men without a bachelor’s degree is 867 per 100,000; for their more-educated peers, it’s just 243. While there’s long been a gap in health outcomes based on education, it looks now more like a yawning gulf.