arstechnica.com – by Annalee Newitz
Imagine a high-density city, and you probably think of something like Mega-City One, full of pollution, poverty, and huge, ugly housing projects. But the reality, according to new research in urban studies, is that high-density city plans offer residents more economic opportunities. Especially for people who want to give their children better lives, high-density cities are the most likely to deliver on the American Dream.
Measuring sprawl and economic mobility
Upward mobility is on the decline in the US. Once billed as a land of opportunity for the poor and hardworking, the country now offers little hope to people born in poverty. Writing in the latest issue of Landscape and Urban Planning, the researchers note that the “chance of upward mobility for Americans is just half that of the citizens of Denmark and many other European countries.” A study from the Brookings Institution found that “39 percent of children born to parents in the top fifth of the income distribution will remain in the top fifth for life, while 42 percent of children born to parents in the bottom fifth income distribution will stay in that bottom fifth.”
But some parts of the country are better off than others. As the researchers explain:
Upward mobility differs significantly across U.S. cities, and some cities such as Salt Lake City and San Jose have rates of upward mobility similar to European countries while other cities such as Atlanta and Milwaukee have lower rates of mobility than any developed country. For example, the likelihood that a child starting in the bottom fifth of the national income distribution will reach the top fifth is 4.4% in Charlotte but 12.9% in San Jose.
What would cause such a pattern? The researchers wanted to find out. Based on previous work in the field, they suspected that it might have to do with urban sprawl. So they set about systematically comparing the amount of sprawl in 990 US counties or county-equivalents with levels of upward mobility. They took their data on sprawl from a recently updated index of US urban sprawl, which measures sprawl by looking at land uses, street connectivity, population density, and location of employment centers. This index found, for instance, that San Francisco, California, and New York, New York, are the nation’s densest areas, while Hickory, North Carolina, and Atlanta, Georgia, are the sprawliest. Data on upward mobility came largely from Harvard’s Equality of Opportunity Project.
What researchers found, after intensive analysis, was that high-density urban areas were correlated with dramatically higher levels of upward mobility. As the compactness of a region doubles, they write, “the likelihood that a child born into the bottom fifth of the national income distribution will reach the top fifth by age 30 increases by about 41 percent.” Spread-out urban sprawl, however, tends to maintain class distinctions from one generation to the next.
Lack of access is the culprit
There are a number of possible reasons why sprawl might be associated with lack of economic opportunity. An obvious one goes back to the “spatial mismatch hypothesis,” first developed in the late 1960s. That hypothesis suggests that the people who need jobs live much too far away from job centers to work there. Even if they could get to the job center, people who live far away from it suffer from “information mismatch,” which is to say they aren’t connected enough to the job center to know about openings and opportunities. The greater the sprawl, the greater the spatial and information mismatch.
By contrast, a higher density city allows people who want jobs to find them more easily. They may literally be right next door.
At the same time, the researchers point out, high-density cities have a couple of characteristics that actually dampen upward mobility: race and class segregation. Even in high-density cities, the poor and the rich tend to be segregated into separate neighborhoods, and this can create cycles of poverty that are very difficult to stop. Children in poor neighborhoods won’t have access to school materials that are as high quality as those in wealthier ones, nor will they have as many after-school enrichment opportunities. So higher density urban plans aren’t a guarantee of more opportunities for all. But even accounting for class segregation, they do offer more chances for upward mobility than sprawling areas do.
What’s fascinating about this study is that it reveals an unexpected relationship between city design and economic opportunity. The researchers suggest it may be time for counties to start factoring the economic fortunes of the next generation into their urban development plans.
Landscape and Urban Planning, 2016. DOI: 10.1016/j.landurbplan.2015.11.012