About a year ago, five prominent members of the U.S. Women’s Soccer team filed an EEOC charge claiming they were unfairly paid as compared to their male counterparts on the U.S. Men’s Soccer team. That charge is still pending.

As we previously blogged, the U.S. Women’s National Hockey team upped the fair pay ante saying they will not play in this year’s World Championship “unless meaningful progress is made” on fair pay issues. How much does fair pay mean to these hockey players? The hockey team is poised to defend its crown as the reigning world champion.

What do these two teams have in common? They win. On the world’s stage, they are more successful than the men in both sports.

So, what’s the issue? While the factual issues, such are relative revenue generation, make for fascinating and complicated arguments, the legal issues under federal law are the same as those in any equal pay claim outside the world of sports.

Are the jobs substantially similar and do they require substantially equal skill, effort and responsibility under similar working conditions? Are there factors other than sex/gender which explain the pay disparity? What about market factors? There are cases under the Equal Pay Act which hold that revenue generation and market pressures can be factors “other than sex” substantiating a difference in pay.

As you watch these battles unfold, keep these legal principles in mind and that recent state pay laws, such as those in California, New York and Massachusetts, are more rigorous and favorable than federal law towards claims of indefensibly unequal pay. Also, consider whether media attention to fair pay in the world of sports and entertainment prompt employees to consider the fairness of their own pay, whether pay differences exist, and whether they can be defended based on neutral pay factors.