You may not even know that April 17, 2013, is a holiday. It's neither a federal holiday nor one made up by Hallmark to sell cards. It is Equal Pay Day, a day designated by the National Committee on Pay Equity (NCPE) each year since 1996 to signify how long into a new year – the date is usually mid-April – a woman must work to earn what her male counterparts had already earned by the end of the previous year. Equal Pay Day also falls on a Tuesday, to signify when men need to start every workweek to end up with the same pay as women by the end of that week. And to honor the holiday, we should all be wearing red, the official color of Equal Pay Day, to signify that women's paychecks are “in the red.”

Equal Pay Day is one of many reminders that pay discrimination remains an important source of gender inequality – one that threatens women's independence and financial security throughout their entire working lives and into retirement. Women continue to make less than eighty cents for every dollar men make, a disparity that cannot be accounted for by labor force commitment, voluntary job choices, or time off to care for children. Indeed, virtually every economist who has crunched the numbers, regardless of his or her ideological slant or background, has concluded that the gender wage gap is at least partially created by pay discrimination – which means paying women less to do the same job simply because they are women.

Despite the entrenched reality of the wage gap, efforts to close it have been largely unsuccessful. And people like Wisconsin governor Scott Walker would be happy to see it grow larger. Walker signed into a law a bill repealing the state's 2009 Equal Pay Enforcement Act (EPEA), which had allowed employees to seek damages in state court for gender-based pay discrimination. This chapter considers the current status of the gender wage gap, some of the obstacles to remediation of pay discrimination claims, and efforts to bolster (or inhibit, as in Wisconsin) women's right to equal pay.