Are the Suburbs Where the American Dream Goes to Die?

Rumors of the American Dream’s demise have been greatly exaggerated–at least in parts of America.

That’s the message of a new study that looks at the connection between geography and social mobility in the United States. {snip} But if you want to move up, don’t move to the South. As you can see in the chart below from David Leonhardt’s write-up in the New York Times, the American Dream is on life support below the Mason Dixon line.

So why does a kid from the bottom fifth in the South or the Rust Belt have such a hard time making it to the top fifth? It’s not how progressive local taxes are. Or the cost of college. Or how unequal a place is. At least not much. The research team of Raj Chetty and Nathanial Hendren of Harvard and Patrick Kline and Emmanuel Saez of the University of California-Berkeley found that these factors only correlated slightly with a region’s social mobility. What seems to matter more is the amount of sprawl, the number of two-parent households, the quality of elementary and high schools, and how involved people are in things like religious and community groups.

The suburbs didn’t quite kill the American Dream, but a particular type did. That’s the low-density and racially-polarized suburbs that have defined places like Atlanta. Indeed, as you can see in the chart below from Paul Krugman, there’s a noticeable relationship between a metro area’s density and its social mobility.

As usual, the elephant in the room here is race. So let’s address it: the researchers found that the larger the black population, the lower upward mobility. But on closer inspection, this has something to do with population density too. I went back to the Census data, and looked at the same ten cities Krugman did, but this time I compared their population-density ratios and the percent of their population that’s black. There isn’t nearly a perfect relationship–look at Boston or Dallas or Houston–but there is a relationship.

Now, it’s not that suburbs outside the South and Rust Belt are some kind of integrated utopia–far, far from it–but rather that density changes things. Well-off whites who work in the city and live close by have an interest in paying for the kind of public goods, like mass transit, that benefit everybody. Well-off whites who live far away don’t. {snip} This malign neglect of infrastructure keeps low-income people from living near or commuting to better jobs–and that’s not a a race issue. Indeed, the researchers also found that whites and blacks in Atlanta both have a hard time moving up. In other words, racial polarization might spur sprawl, which makes cities less likely to invest in their infrastructure–and underfunded infrastructure hurts low-income people of all races.

{snip}