Employers in some fields may give extra financial incentives to young black women, who graduate from college at higher rates than young black men, said Roderick Harrison, a researcher at the Joint Center for Political and Economic Studies, a think tank that studies minority issues.
''Given the relative scarcity, if you are a woman in the sciences -- if you are a black woman -- you would be a rare commodity," Harrison said.
Because study in the area is limited, it is hard to pinpoint specific reasons, said Barbara Gault, research director at the Washington-based Institute for Women's Policy Research.
''It could be the fields that educated black women are choosing," she said. ''It also could be related to the important role that black women play in the total family income in African-American families."
Nearly 39 percent of families headed by a single black woman were in poverty, while the figure was 21 percent for comparable white women, according to census estimates released last year.
A white male with a college diploma earns far more than a similarly educated nonwhite man or woman -- in excess of $66,000 a year, according to the Census Bureau. Among men with bachelor's degrees, Asians earned more than $52,000 a year, Hispanics earned $49,000, and blacks earned more than $45,000.
Workplace discrimination and the continuing difficulties of minorities to get into higher-paying management positions could help explain the disparities among men, specialists say.
Demographics may offer an explanation: There are millions more college-educated white men in better-paying jobs than there are black, Hispanic, or Asian men.
Minorities also suffered more financially as a result of the 2001 recession and its aftermath, as has been the case with past economic downturns, said Jared Bernstein, chief economist with the Economic Policy Institute.
The figures are from the Census Bureau's annual look at educational achievement in America, culled from a survey in March 2004. Questions about income were asked for the previous calendar year.