For decades, college graduates in America tended to buy houses in the suburbs even if they worked in the city. But that’s changing. According to a new study by the Federal Reserve Bank of Cleveland, American inner cities are now better educated than their surrounding suburbs—a finding that holds true across the country, from D.C. to Chicago to Houston to Portland. In 1980, most college graduates lived 10 to 25 miles away from cities, and now the majority of them live within 15 miles of city centers. This trend is fueling the resurgence of cities across America, cutting down on long commutes, which can help the environment at the same time as it revitalizes urban areas.