The revival of America’s core cities is one of the most celebrated narratives of our time—yet, perhaps paradoxically, urban progress has also created a growing problem of increasing inequality and middle-class flight. Once exemplars of middle-class advancement, most major American cities are now typified by a “barbell economy,” divided between well-paid professionals and lower-paid service workers. As early as the 1970s, notes the Brookings Institution, middle-income neighborhoods began to shrink more dramatically in inner cities than anywhere else—and the phenomenon has continued. Today, in virtually all U.S. metro areas, the inner cores are more unequal than their corresponding suburbs, observes geographer Daniel Herz.
Signs of this gap are visible. Homelessness has been on the rise in virtually all large cities, including Los Angeles, New York, and San Francisco, even as it declines elsewhere. Despite numerous exposés on the growth of suburban poverty, the poverty rate in core cities remains twice as high; according to the 2010 census, more than 80 percent of all urban-core population growth in the previous decade was among the poor. For all the talk about inner-city gentrification, concentrated urban poverty remains a persistent problem, with 75 percent of high-poverty neighborhoods in 1970 still classified that way four decades later.