Although the National Labor Relations Act bans employers from preventing discussion of wages and working conditions, the provision is vague, and the practice is actually fairly common. Last year, in a nationwide survey by the Institute for Women’s Policy Research, half of adults reported that discussions about pay were either prohibited or discouraged at their workplace. That’s why some officials have pursued additional laws specifically protecting the right. Colorado, Michigan, Illinois, the District of Columbia and California have passed such measures, and earlier this year, President Obama signed an executive order on wage transparency for federal contractors.