The rise of economic inequality has become a staple of policy debates and stump speeches. Less visible is the way the rise has altered the landscape of America’s urban neighborhoods. Two books should help change that. Matthew Desmond, an urban sociologist at Harvard, has delivered a jolt with Evicted: Poverty and Profit in the American City, a close-up portrait of life on the lowest end of Milwaukee’s private rental market. In Ghetto: The Invention of a Place, the History of an Idea, Mitchell Duneier, a sociologist at Princeton, steps back and turns his attention toward other scholars of poverty, examining how they have changed the way the rest of us understand the ghetto. To begin to explain why upward mobility lags in the United States compared with most other countries in the developed world, Desmond and Duneier agree, we need to think anew about the most isolated neighborhoods—about what keeps those places so separate, and their residents so stuck in them.