Years ago, Howard Stern quipped, “What is the best thing about having a woman boss?”

His answer: “You make more money than she does.”

And after another year of watching Equal Pay Day come and go, the reality underlying Stern’s clumsy wisecrack still rings true. According to recent Census statistics, women's earnings were 77.4 percent of men's in 2010, based on the median earnings of all full-time, year-round workers. This figure has increased incrementally since the 60s, but has barely moved since 2001. At our current rate of change, women will achieve parity with men in the year 2056.

Many of us wonder how this dynamic could persist today. A recent study by Allstate showed that more than a quarter of women believe that – based on their gender – they have been discriminated against in the workplace, including being “denied a promotion, raise or opportunity.” That one in four women feel discredited by their gender is a setback, not progress.

As tempting as it may be to look for one singular source of the problem to lobby (or blame), the issue of the wage gap has many tentacles. Some of these causes are systemic, others are individualistic and behavioral, and still others are cultural and incredibly nuanced. Take for example that there are more women than men concentrated in low-paying functions and industries, often referred to as “pink ghettos.” Many of these jobs have low pay ceilings and less than optimal advancement prospects.  Women also “offramp” from the paid workforce more often than men, hurting their long-term earnings and savings. Add to this that the typical American workplace promotes lack of transparency, even secrecy, around pay scales, which only hurts matters further.

But there is an action—a skill—that can help women correct some of this inequality on their own.

I’m talking about negotiation.

As a group, we as women negotiate four times less often than our male counterparts.  And I’d argue that not asking for what we want makes us four times less likely to get plum assignments, promotion opportunities and certainly higher pay. Another case in point: I recently collaborated on a survey with LinkedIn, whose results showed that only 26 percent of women say they feel confident when negotiating. Yes, our current economic backdrop does nothing to encourage negotiating on the job; after all, nothing frightens people out of making requests like a recession. But apprehension doesn’t need to lead to inaction. And as anyone knows who’s made a request, the timing will never be perfect.

Women can learn and practice strategies that get them to the negotiating table more often and help them hold their own once they’re there. Out of the gate, we need to aim high, with aggressive proposals that represent the highest we can possibly ask for, while still being able to rationally defend our stance. Rather than simply acquiescing to a flat-out “no” or a negative appraisal of an idea, we as negotiators can get more of what we want by holding out for hard data and facts. We can and should ask questions like, “Can you explain how you arrived at that conclusion?” and “How are decisions like these determined?” We need to insist on objective criteria rather than quickly accept defeat.

As economist Sylvia Ann Hewlett has pointed out, when women have a high-ranking mentor or advocate in their corner, also known as a sponsor, they’re more likely to ask their managers for a stretch assignment. What’s more, women with sponsors are more likely to ask for raises than women without them. We must remember that our ability to negotiate effectively is driven in part by how we view our counterpart. By purposefully seeing them in a non-deferential, equal-to-equal kind of way, we can avoid inflating their power and lessening ours. We need to value our own résumés.

No, negotiating more often is not a panacea for the wage gap. But when we don’t negotiate our salaries, we leave thousands, even millions, of dollars on the table unclaimed. This affects us negatively today, drastically dwarfing the retirement savings we work hard to accumulate and the extent to which we can provide for our families. What else will it take for us to see that our own earnings are a lifeline? Consider this. Nearly half of all marriages end in divorce and women live longer than men.

If you’re tired of hearing about unequal pay, then why not do something that can narrow the gap right now? Encourage a sister, niece, daughter, wife or yourself to go ask for it.

Selena Rezvani is author of the new book, PUSHBACK: How Smart Women Ask—And Stand Up—For What They Want and co-president of Women’s Roadmap. Follow her on Twitter at @SelenaRezvani.

More from On Leadership :

Inside the head of an overpaid CEO

The rolodex that redefined power

How to completely destroy an employee’s work life

Like On Leadership? Follow us on Facebook and Twitter :

On Leadership: @post_lead | Editor: @lily_cunningham