Money may not buy love, but it appears to buy years.

Economist Barry Bosworth at the Brookings Institution crunched the numbers and found that the richer you are, the longer you’ll live. And it’s a gap that is widening, particularly among women.

Mr. Bosworth parsed this data from the University of Michigan’s Health and Retirement Study, a survey that tracks the health and work-life of 26,000 Americans as they age and retire. The data is especially valuable as it tracks the same individuals every two years in what’s known as a longitudinal study, to see how their lives unfold.

The good news is that men of all incomes are living longer. Yet the data shows that the life expectancy of the wealthy is growing much faster than the life expectancy of the poor.

Here’s the sort of detail this remarkable data set can show. You can look at a man born in 1940 and see that during the 1980s, the mid-point of his career, his income was in the top 10% for his age group. If that man lives to age 55 he can expect to live an additional 34.9 years, or to the age of 89.9. That’s six years longer than a man whose career followed the same arc, but who was born in 1920.