Income mobility is pretty much the core of the “American dream,” the idea that people who begin their lives with little can work hard and improve their lot. But such depends on where you live. Some cities and neighborhoods are much more amenable to income mobility than others.
So check this out:
(Note: The chart shows the effect on boys whose parents have incomes in the bottom quarter. The effect is pretty much the same for girls.)
Via Kevin Drum at Mother Jones, the chart is from a working paper he tracked down that examines the effect of low-income children moving to different (“better”) neighborhoods. Of all the factors that were studied, commute time was the most significant, eclipsing even things like crime rates, parent incomes, social capital, and segregation.
Why might that be? Drum doesn’t have any clear answers. The erosion of family time by long distance daily travel certainly seems like a bad idea!
What do you think?
The Chetty paper cited by Drum is the second in a series of papers; the first paper discusses these relationships in greater detail.
The likely cause, in a nutshell: commute time is most likely a proxy for racial and economic segregation, which in turn deprives families of jobs and other resources they need to overcome intergenerational poverty. Areas with greater commute times tend to be characterized by high degrees of segregation and sprawl; in other words, they tend to be characterized by living patterns in which poor families are not geographically proximate to various sources of economic opportunity.
See this passage (from http://qje.oxfordjournals.org/content/129/4/1553.full): “Another mechanism by which segregation may diminish upward mobility is through spatial mismatch in access to jobs (Kain 1968; Kasarda 1989; Wilson 1996). We explore this mechanism in column (6) by correlating upward mobility with the fraction of individuals who commute less than 15 minutes to work in the CZ, based on data from the 2000 census. Areas with less sprawl (shorter commutes) have significantly higher rates of upward mobility; the correlation between commute times and upward mobility is 0.605. Column (7) shows that commute times remain a significant predictor of upward mobility in a multivariable regression but income segregation does not.
These results are consistent with the view that the negative effects of segregation may operate by making it more difficult to reach jobs or other resources that facilitate upward mobility.”
In the Twin Cities, lengthy commute time doesn’t even have to equal long distance travel- someone from Mac Groveland or Highland Park could drive to a job in about 20 minutes where someone taking transit from the same area would get to the same job location in about 40 minutes.