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."
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.Urban sprawl is often criticized because as people spread out they use a lot more fuel driving around, and in the process they are probably building their homes on valuable agricultural land. But now we have another type of criticism--the social criticism layered onto the ecological one.
Keep in mind, though, that the research I discuss in my book emphasizes that we humans like to have it both ways--living near enough to the high density city to take advantage of it, but living far enough away so that we don't have to be annoyed by that high density. As with most things in life, there are no easy answers.