City Observatory readers will be familiar with the findings of Raj Chetty and his colleagues in the Equality of Opportunity Project. In a revelatory use of big data, they used anonymized tax records to track the lifetime earnings of kids growing up across the United States. The results show that the neighborhood and metro area one grows up in has a huge impact on your lifetime earning prospects. Strikingly, kids from low income families growing up in some neighborhoods, especially those with mixed incomes and lower levels of racial segregation fare better.

The Equality of Opportunity Project’s research casts doubt on some traditional economic development nostrums — i.e., having more jobs nearby or faster job growth doesn’t seem to be associated with intergenerational economic mobility — and put more emphasis on a wide range of neighborhood effects: for example, intergenerational mobility is positively correlated with the number of employed adults in a neighborhood and with measures of social capital. This suggests that successful mixed income neighborhoods play a key role in helping kids escape poverty.

To shift gears a bit, if you read City Observatory and Strong Towns regularly, you’re also familiar with Walk Score, the ubiquitous easy-to-interpret index of walkability. We and other scholars have used Walk Score to show that walkability commands a premium in real estate markets; more walkable homes, all other factors held constant, tend to be much more valuable than homes that are more car-dependent. A growing body of public health research also confirms that walkability has significant health benefits: people who live in more walkable areas walk more and are healthier.

Now, let’s combine these two threads: the geography of intergenerational economic mobility and walkability. A new paper from psychologists Shigehero Oishi, Minkyung Koo and Nicholas Buttrick does just that, looking at the correlation between Walk Score and intergenerational economic mobility.

Oishi, Koo and Buttrick aggregate data from the Equality of Opportunity Project’s estimates of intergenerational economic mobility in “commuting zones” and compare them to the overall level of walkability in the area. (“Commuting Zones” are a geographical unit that usually encompasses an entire metro area and surrounding rural areas. The US is divided into 377 such zones.)

The study finds that, after controlling for the “big five” factors that Chetty et al.’s research showed tended to influence intergenerational economic mobility — percentage of African Americans, degree of income inequality, quality of K–12 education, social capital, and percentage of children with single mothers — that a commuting area’s Walk Score added a statistically significant and positive effect on intergenerational economic mobility. Including walkability in a model of intergenerational economic mobility explained an additional 10 percent of the variation in mobility rates among commuting zones. As the authors conclude:

Using tax data from almost nine million Americans born between 1980 and 1982, Study 1 demonstrates that upward social mobility is substantially higher in more walkable areas (r .390). The more walkable an area is (as indexed by Walkscore.com), the more likely Americans whose parents were in the lowest income quintile are to have reached the highest income quintile by their 30s. This relationship holds above and beyond factors previously used to explain upward mobility, factors such as income inequality and social capital, and is robust to various political, economic, and demographic controls; to alternate specifications of upward mobility; and to potentially unspecified third variables. [Emphasis ours.]

This is encouraging evidence. It suggests that regions that are more walkable tend to have better opportunities for kids from low income families to make connections. It may also be that walkability is correlated with other factors, like social capital, that maximize opportunities.

Oishi, Koo and Buttrick explore these possible explanations by looking at other data on commuting and car ownership and on walkability and a self-reported sense of belonging. Their data show that in more walkable areas, economic success is less correlated with car ownership (suggesting one way that economic mobility is enhanced by greater walkability). The findings on a sense of belonging and intergenerational mobility are less clear; the relationship, if anything is indirect:

. . . although the direct association between walkability and upward social mobility was not significant, those living in a walkable neighborhood and those who walked more in their everyday lives felt a greater sense of belonging, which was in turn associated with upward social mobility

The data support the notion that walkability is correlated with intergenerational economic mobility. One limitation of the headline analysis of the Chetty et al. data is that they are aggregated at the level of commuting zones. We know that that both walkability and intergenerational economic mobility vary substantially within metropolitan areas; different neighborhoods within a metro area can either be car-dependent or highly walkable. It seems like the next logical step in this research is to look to see whether this same correlation holds for smaller areas.

Top photo via Sai De Silva.