Women have made tremendous gains in education, employment and earnings in the past 50 years, but there is still a persistent gender pay gap. Even young working women continue to lag behind men.

Among recent college graduates, full-time working women on average earn 82% of what their male peers earn, according to a study released todayby the AAUW (American Association of University Women). The report is based on 2009 U.S. Department of Education statistics.

The result is similar to a broader study by the Institute for Women’s Policy Research, which said that in 2011, the gender wage gap for working women of all ages was 82.2%. It found that women earned less in every occupation except bookkeeping, accounting and auditing clerks.

Women earn less for a several reasons, experts say, including their college majors, occupation and the number of hours they work. Today, women still tend to enter lower-paid fields such as education and social sciences, while men typically major in engineering and computer science.

AAUW took a closer look at the difference between men and women who enter the same occupation. The apples-to-apples comparison found that women still earned about 7% less than their male counterparts. Give their similarities, this pay gap is unexplained, and gender discrimination is one potential factor, the study says.

“A lot of people think that stereotypes are a thing of the past,” says Catherine Hill, director of research at AAUW. “But we see that these things are continuing and real.”

If a young man and woman fresh out of college with the same degree walk into a large firm, typically, the man can get placed in higher-wage jobs than the woman, says Heidi Hartmann, president of the Institute for Women’s Policy Research.

Unfortunately, private-sector workers are discouraged from or even penalized for sharing information about their salaries with co-workers. “Many times, younger women are shocked to learn that they are not on equal footing with men,” says Fatima Goss Graves, vice president for education and employment at the National Women’s Law Center.

Negotiating a salary can make a difference in earnings. But some research has found that women are less likely to negotiate for higher salaries, and other studies have shown that women who do negotiate are perceived differently than men and may be penalized, Graves says.

Because of the pay gap, young women workers deplete more of their earnings to pay for their costly student loan debt. “What we find is that women who are paying for college loans after graduation are paying a bigger chunk of their smaller paychecks,” Hill says. “They have less money to live on just one year after graduation.”

More than half of full-time working women graduates, 53%, were paying a greater percentage of their earnings toward student loan debt than a typical worker could reasonably afford to pay, the AAUW study found. That’s compared with 39% of men.

What can be done about the pay gap? “Women could pick higher-paying majors, such as nursing, computer science, math, science and engineering” Hartmann says. “The employer has the responsibility to ensure that they do not treat men and women differently.

“And the government also has responsibility. We have equal-pay laws that have been on the books for a very long time, but we still have unequal pay, which suggests a need for stronger enforcement or new legislation.”