There is nothing that this legislation can do that the Equal Pay Act of 1963 hasn't already accomplished. Thanks to said law, pay discrimination based on sex has already been a federal crime for more than half a century, making the gender pay gap a myth. The 78¢ statistic comes from the Income, Earnings, and Poverty Data from the 2007 ACS released by the Census Bureau. It says that in aggregate, the national median income of women was 78% of that of men. It is actually a gender earnings gap, and it's also a national average, not a universally applicable paradigm. It exists because generally, women don't take the same jobs, work the same hours, or negotiate their salaries as aggressively as men do. If women really were universally paid 23% less than men, then there would be no men in the work force at all. A man would have to be overqualified just to get hired.