When the American Association of University Women Educational Foundation recently released its new "Behind the Pay Gap" study detailing how women persistently and consistently earn less than men, I wasn't too surprised. After adjusting the data to address known factors such as occupational differences and parenthood, the researchers still determined that there's a sizable pay gap.

New female college graduates earn about 80 cents for every dollar earned by their male counterparts. So right out of the gate, women are 20 percent behind. After 10 years, that wage gap widens to 31 percent.

Men not only earn more, they also run more: Ten years after graduation, men tend to have more authority and management responsibility than women.

One of the study's suppositions is that sex discrimination might be at play here. Another is that women tend to gravitate toward lower-paying professions such as education, while higher-paid fields such as engineering are veritable boys' clubs.

Those are all valid assumptions, but I think that there's another reason: Women aren't as good as men when it comes to standing up for what they're worth. Even when women are given a raise, their tendency is to take what's offered without negotiating — even if it's less than what they deserve. And that has plenty to do with the wage gap.

In their book "Women Don't Ask: Negotiation and the Gender Divide," Linda Babcock and Sara Laschever report that women are 2.5 times more likely than men to say they feel "a great deal of apprehension about negotiating." The authors estimate that a woman's lack of negotiating skills in her first job can end up costing her about $500,000 in forgone earnings over her career.

Clearly, negotiation is one important area where women can shrink the wage gap. Here are a few tips:

n Good soldiers are destined to be underpaid.

Don't wait for your boss to miraculously give you a raise and promote you. You need to step up and state your case.

If you're just out of school and have your first job, after you've negotiated your starting salary, develop a great reputation over at least a year before you start agitating for more money or responsibility.

If you don't get an annual formal review from your boss, insist on one. The outcome should be a written agreement — signed by you and your boss — of what you achieved in the past year and your goals for the upcoming year.

n It's not personal.

Your boss should pay you what you deserve as a sign of respect. Don't hesitate to bring up your compensation or the timetable for a promotion. This is about the business of you managing your career. Don't make it an open-ended request along the lines of "I want a raise." Be specific: "I deserve a raise of at least 5 percent." That wording sets the tone for the negotiation.

n Document your accomplishments.

In advance of the salary negotiation, send your boss a one-page rundown of your accomplishments over the past year. List the tasks/goals that you were given during the year and how you met those expectations. Then note the ways you went above and beyond those expectations.

n State your case.

Explain your value to the company with professionalism and confidence.

I recently heard from a woman who'd known that she was being underpaid and raised the issue with her boss, who came back with a 5 percent raise. She appreciated his effort, but knew that still wasn't properly valuing her work. So she got him and an HR rep to listen to her case. After a few weeks of back and forth, she ended up with an 8 percent raise, stock options and a promotion.

n Be prepared to counter.

Just because you state your case doesn't mean that you'll get what you want. Don't get mad, but don't settle. Keep the conversation going. Ask for concrete reasons why the raise is low or the promotion isn't forthcoming.

For every reason given, counter with an action step such as a written agreement for a midyear review to reconsider your status.

n Be prepared to walk.

I tell people that they need eight months of living expenses saved up in an emergency fund because two or three months isn't sufficient. You want to negotiate with your boss with the knowledge that if you can't get what you want, you can afford to quit.

Don't quit without having another job lined up — it's often easier to find a new job while you're still employed. But with a savings account safety cushion, you know that if you can't get your company to pay you what you're worth, you have the flexibility to leave and go someplace that will.

— Suze Orman is a best-selling author and Emmy award-winning TV host. For details, visit http://www.suzeorman.com.