For decades most U.S. cities had a decaying inner core surrounded by suburbs that grew increasingly wealthy with distance. But now many cities are showing a new pattern of affluence and poverty. Well-educated millennials in their 20s and 30s who have considerable income are moving into rejuvenated downtown areas (red shapes at center of graphic below). They are driving up rents, which is forcing some poorer residents to the inner suburbs, vacated by suburbanites who have moved farther out. These inner suburbs may pose the next big revitalization challenge for urban planners: postwar houses are aging, and basic city services such as mass transit are often lacking.

SOURCE: THE CHANGING SHAPE OF AMERICAN CITIES, BY LUKE J. JUDAY. DEMOGRAPHICS RESEARCH GROUP, WELDON COOPER CENTER FOR PUBLIC SERVICE, UNIVERSITY OF VIRGINIA, MARCH 2015; Graphic by Katie Peek