'But this research suggests there are still problems for women that relate to college.'

She used data from the National Longitudinal Study of the High School Class of 1972 and the National Education Longitudinal Study of 1988.

With these data sets, she was able to compare women who graduated from high school in 1972 and 1992.

She compared the incomes of college graduates seven years after their high school graduations, in 1979 and 1999. Both samples included about 10,000 cases.

Findings showed the income gap between college-educated men and women declined significantly in 20 years -- in 1979, women's earnings were 78 percent of their male counterparts, but by 1999 the women were earning 83 percent as much as men.

Bobbitt-Zeher presented her research at the annual meeting of the American Sociological Association, San Francisco.