Indeed, the hollowing out of the middle class, continuing stagnation of wages, and new evidence on the lack of upward mobility across generations all strike at the very heart of the American ideal.
In one widely reported study, the odds of a child from a poor family climbing up the income ladder to reach the top fifth of the income bracket as an adult are less than 10 percent for the nation (Chetty et al. 2014b). Meager odds of upward mobility challenge the implicit “social inequality contract” that, for better or worse, has long held in American society.
The facts on individual income mobility are crucial, of course, but they tell only half the story. The other half pertains to the prospects of change in one’s community of residence: individuals are born into, grow up in, and become adults in neighborhoods that are also highly unequal. Concentrated poverty, violence, and poor school quality, for example, tend to cluster together at the neighborhood level and bear on life chances across a variety of outcomes. More generally, the persistent fact of neighborhood differentiation across the sweep of urban history (Smith 2010; Smith et al. 2014) suggests that spatial arrangements constitute a fundamental organizing dimension of social inequality (Massey 1996; Sampson 2012; Sharkey 2013).