Having a college degree, along with the higher income that such a credential commands, generally increases your odds of retiring on time. Now, a new study shows that your degree is likely to keep giving you a financial edge even if you need, or choose, to keep working in your 60s and beyond.

For a recent analysis by the Institute for Women’s Policy Research , economist Heidi Hartmann and sociologist Jeff Hayes analyzed Census Bureau data from the years 2005 to 2009, covering people ages 50 and up who were still employed. People with a bachelor’s degree or postgraduate education made up about one third of the pool of people studied.

At ages 50 to 55, the average man with a bachelor’s degree earned about $28 an hour, roughly 42% more than the average man with a high-school diploma or less. Women with bachelor’s degrees earned about $21 an hour, 37% more than their high-school-educated peers. At retirement age, degree-holders saw their income drop faster than those with just a diploma, but the wage gap remained: At age 70, men with bachelor’s degrees were making 31% more than their high-school educated peers; women with degrees earned 21% more.

More important: Degree-holders’ jobs tend to be less physically demanding, and as a result, as study author Heidi Hartmann noted in an interview this week with NPR’s Ina Jaffe , those folks “have the likelihood of working, two, three, four times more at older ages.” More hours worked plus higher wages adds up to a big edge in total earnings: Hartmann and her co-author Jeff Hayes estimated that the average two-bachelor-degree couple would bring in a total of $202,000 in earnings from work after age 65, compared to about $79,000 for a working couple that only finished high school.

Currently, men of retirement age are much more likely than women the same age to hold relatively high-paying knowledge jobs, but Hartmann told Jaffe that she expects that disparity to shrink steadily as women continue to establish themselves in age-proof professions like law, medicine and politics.