(CNN) -- If dating is a numbers game, then single ladies should consider this: A Pew Research Center report this year noted a surge in women between the ages of 30 and 44 making more money than their husbands.

Women made more money than men in 22 percent of married couples surveyed in 2007, compared with 4 percent in 1970. While men make more money overall and hold more management positions, women are making greater gains.

"The supply of men has changed," said D'Vera Cohn, senior writer at the Pew Research Center's Social and Demographic Trends project. "The pool of college educated men isn't growing as rapidly as it is for women."

There is also a gender shift in the realm of education. Women represent nearly 60 percent of students holding advanced degrees in areas such as medicine, law, business and graduate programs, the U.S. Census reported in April.

Researchers have found educational attainment to be a higher priority among couples than ever. Popular online dating sites Match.com and eHarmony report that romances happen occasionally between educated, professional women and men who are less educated or have a lower salary.

Leah MacIsaac-Ruff, 45, works 11-hour-plus-days as a technology vice president at a Wall Street firm. She has a college degree. So does her husband, Doug, 43, who walks dogs for a living.

MacIsaac-Ruff may be the breadwinner, but she finds her husband's career choice refreshing.

"If I were to marry a type-A personality and we sat on our computers side by side in the evenings, I think I'd die," she says. "I think I'd be in a cold relationship. The last thing I want is to go home to an investment banker."

Despite their job disparities, the couple share enjoyment of the opera and theater. When they attend her upscale corporate events, she isn't embarrassed when people ask about her husband's profession. Instead, people are intrigued by his dog-walking job.

"It doesn't bother me one bit that she makes more money," said her husband one morning as he was gearing up to walk 15 dogs. "I couldn't be more proud of what she's done in the business world."

The recession has shaken some traditional gender expectations, said several marriage and family experts. About 4.7 million jobs were lost among men during the recession, according to April figures from the Bureau of Labor Statistics. Two million women lost their jobs, the report said, leaving more women to become sole supporters of their families.

Particularly among the millennial generation, people are less likely to have gripes with a woman who earns more and has more education, said Nicole Johnson, a spokeswoman for the National Association of Professional Women. Her organization represents 150,000 women, with a majority working in a white-collar profession.

"At one point, the stereotype was a man might feel inferior to a woman who is at a higher point in her career than he is," Johnson said. "I think that's dissipated a bit, where there aren't these built-in expectations of who should be above."

Educated, professional women exposed to men working lower-paying jobs growing up are more likely to date them, said Amadu Jacky Kaba, a sociology professor at Seton Hall University in New Jersey. "When they see a hard-working garbage collector or different kinds of lower-level jobs, then they trust them," Kaba said.

Robin Coates, 45, of Mobile, Alabama, found starting a relationship with her boyfriend, Sam, a 39-year-old who installs floors, to be tricky. Coates works as a creative director and has a college degree. She, too, makes more money than her boyfriend, who dropped out of school in the eighth grade.

"Many years ago he said, 'I'm not the guy for you. You need to be dating a guy with a suit and tie,' " she said.

Coates said they have dated for eight years and plan to get married soon.

Dating a man who makes less money or hasn't attained as high a level of education can be difficult, said Whitney Casey, a dating expert at Match.com, the online dating site for singles. She said the differences can work if the couple has similar goals and values.

"There are benefits, too," she said. "It can open your world and make you become a better-rounded person."

EDITOR'S NOTE: A previous version of this story included examples that have been removed because they contained errors.