The earning power of young single women has surpassed that of their male peers in metropolitan areas around the U.S., a shift that is being driven by the growing ranks of women who attend college and move on to high-earning jobs.

In 2008, single, childless women between ages 22 and 30 were earning more than their male counterparts in most U.S. cities, with incomes that were 8% greater on average, according to an analysis of Census Bureau data released Wednesday by Reach Advisors, a consumer-research firm in Slingerlands, N.Y.

Real Time Economics Cities Where Women Outearn Male Counterparts

The trend was first identified several years ago in the country's biggest cities, but has broadened out to smaller locales and across more industries. Beyond major cities such as San Francisco and New York, the income imbalance is pronounced in blue-collar hubs and the fast-growing metro areas that have large immigrant populations.

The greatest disparity is in Atlanta, where young, childless women were paid 121% the level of their male counterparts, according to Reach Advisors.

These women have gotten a leg up for several reasons. They are more likely than men to attend college, raising their earning potential.

Between 2006 and 2008, 32.7% of women between 25 and 34 had a bachelor's degree or higher, compared with 25.8% of men, according to the Census.

And men have been disproportionately hit by heavy job losses in blue-collar industries.

"I expect the trend to continue," said Andrew Beveridge, a professor at Queens College at the City University of New York, who has studied the phenomenon.

While these particular women earn more than their male peers, women on the whole haven't reached equal status in any particular job or education level. For instance, women with a bachelor's degree had median earnings of $39,571 between 2006 and 2008, compared with $59,079 for men at the same education level, according to the Census.

At every education level, from high-school dropouts to Ph.D.s, women continue to earn less than their male peers.

Also, women tend to see wages stagnate or fall after they have children.

Write to Conor Dougherty at conor.dougherty@wsj.com