The study, by the American Association of University Women, examined the pay gap between young men and women working full time in 2009. They had an average age of 23, were unmarried and had no children. A year after their college graduation in 2007/2008 -- the latest data available -- was tough time to get hired, but the majority of college graduates were working full-time one year after graduation.
The study, by Christianne Corbett and Catherine Hill, said education and occupational differences between men and women help explain the pay gap. Choice of a college major is an important factor driving pay differences, men are more likely than women to major in fields like engineering and computer science and work in higher-paying sectors of the economy. Women major more in education and the social sciences, which pay less.
However, the report found one year after graduation, a pay gap existed between women and men who majored in the same field.
For example, among business majors, women earned about $38,000, while men earned just over $45,000. Among full-time workers in the for-profit sector, women earned $35,841 -- 80 percent of their male counterparts average of $44,638.
This $7,000 pay gap repeated yearly would result in the women losing out on about $1.2 million at retirement if the money was invested with an annual 6 percent rate of return.
Differences in the number of hours worked also affected earnings. One year out of college, women in full-time jobs reported working 43 hours per week on average, and men in full-time jobs reported working an average of 45 hours per week.
Nonetheless, the study found a hypothetical pair of graduates -- one man and one woman from the same university who majored in the same field both working full-time one year later, the same number of hours each week, in the same occupation and sector -- a woman would earn about 7 percent less than the man.