Is it possible there’s such a thing as a reverse gender gap? A new study says that young, single, and childless women under 30—who live in cities—make more money than their male counterparts. But if any one of those factors changes—for instance, married women, or women who don’t live in a city—they end up earning less money than men. James Chung of Research Advisers, who spent more than a year analyzing Census data, said education is the reason for salary increases for women. Those with college degrees tend to earn more than those without, and more degrees are awarded to women than men. Even though some cities did not hold true on the trend, those cities tended to have industries that were based more on male-dominated industries, such as software development or military-technology contracting.