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	mobility-sequence Mobility: Connections [ Part of a sequence of posts on income mobility ] If a child's high schools doesn't explain why neighborhoods have a causal effect on adulthood income, what does? Probably the most intuitive answer is social connections. Married Parents One of the things Chetty et al found is that one of the best predictors of whether a commuting zone (CZ) is good is whether there is a low rate of single-parent households. The obvious explanation is that children from single-parent homes do worse, but this turns out to not be the main effect. Chetty et al didn't publish this level of detail on single-parenthood at the census-tract level, but what they did publish is consistent with the above (see "Family Structure and Social Capital" from The opportunity atlas: Mapping the childhood roots of social mobility). Specifically, see Figure XII from the online appendix of Where is the land of opportunity? The geography of intergenerational mobility in the United States, where the authors document that the percent of single mothers in a commuting zone predicts upwards mobility overall (A) and for the children of married parents specifically (B): There are four hypotheses for the first graph: Living in an area with single mothers reduces mobility. A confounder causes both high single motherhood rates in an area and reduced mobility. Not having a dad reduces mobility. A confounder causes not having a dad and reduces mobility. The fundamental problem is that as we move right on the graph, a child is both raised in areas with more single motherhood and also is more likely to themselves be raised by a single mother. The relationship in the second chart, on the other hand, can only be caused by (1) and (2). Therefore, the difference in the slopes is the combined effect of (3) and (4). The slope of the first graph is 0.84 while the slope for the second is 0.70. This leaves a difference of 0.14. This is consistent with the theory that being raised without a dad causes a 14pp drop in childhood income. It is also consistent with the theory that confounders causes both a 14pp drop in childhood income and single motherhood. There is a little rub here. Chetty et al define parent income as the mean income of the parents with tax returns. This means a couple making $60k and $40k is considered to have equal rank as a single mother make $50k. At first glance, this seems absurd. After all, the former household has double the resources of the latter. However, as we discussed previously, genes matter a lot and financial resources typically don't, so this definition should actually actually better in practice. Still, there are some issues here. For instance, married mothers are about 4pp more likely to be employed Pepin. If this is an effect of being married, this makes using their earnings as a measure of genetic ability-to-earn biased upwards relative to unmarried women. I don't think we have any existing great ways to figure out which theory is correct here. We can be pretty sure confounders are a generally a problem, since studies that examine divorce and parental death frequently find quite different effects Mack Corak. What all of this evidence suggests is that growing up in neighborhoods with high rates of single-motherhood has a much larger (negative) effect than growing up in a single-parent household. There are two interpretations here: either whether your father stuck around barely matters at all or neighbors matter a great deal. Economic Connectivity todo Social capital I: measurement and associations with economic mobility Social capital II: determinants of economic connectedness Chetty, R., Jackson, M. O., Kuchler, T., Stroebel, J., Hendren, N., Fluegge, R. B., ... & Wernerfelt, N. (2022). Social capital I: measurement and associations with economic mobility. Nature, 608(7921), 108-121. https://doi.org/10.1038/s41586-022-04996-4 Chetty, R., Jackson, M. O., Kuchler, T., Stroebel, J., Hendren, N., Fluegge, R. B., ... & Wernerfelt, N. (2022). Social capital II: determinants of economic connectedness. Nature, 1-13. https://doi.org/10.1038/s41586-022-04997-3 Hymowitz, K. (2022). Raj Chetty’s Family Problem. Institute for Family Studies. https://ifstudies.org/blog/raj-chettys-family-problem Chetty, R., Hendren, N., Kline, P., & Saez, E. (2014). Where is the land of opportunity? The geography of intergenerational mobility in the United States. The Quarterly Journal of Economics, 129(4), 1553-1623. https://doi.org/10.1093/qje/qju022 Chetty, R., Friedman, J. N., Hendren, N., Jones, M. R., & Porter, S. R. (2018). The opportunity atlas: Mapping the childhood roots of social mobility (No. w25147). National Bureau of Economic Research. https://doi.org/10.3386/w25147 Pepin, J. R., Sayer, L. C., & Casper, L. M. (2018). Marital status and mothers’ time use: Childcare, housework, leisure, and sleep. Demography, 55(1), 107-133. https://doi.org/10.1007/s13524-018-0647-x Mack, K. Y. (2001). Childhood family disruptions and adult well-being: The differential effects of divorce and parental death. Death studies, 25(5), 419-443. https://doi.org/10.1080/074811801750257527 Corak, M. (2001). Death and divorce: The long-term consequences of parental loss on adolescents. Journal of Labor Economics, 19(3), 682-715. https://doi.org/10.1086/322078

mobility-sequence

Mobility: Connections

[ Part of a sequence of posts on income mobility ]

If a child's high schools doesn't explain why neighborhoods have a causal effect on adulthood income, what does? Probably the most intuitive answer is social connections.

Married Parents

One of the things Chetty et al found is that one of the best predictors of whether a commuting zone (CZ) is good is whether there is a low rate of single-parent households. The obvious explanation is that children from single-parent homes do worse, but this turns out to not be the main effect.

Specifically, see Figure XII from the online appendix of Where is the land of opportunity? The geography of intergenerational mobility in the United States, where the authors document that the percent of single mothers in a commuting zone predicts upwards mobility overall (A) and for the children of married parents specifically (B):

There are four hypotheses for the first graph:

Living in an area with single mothers reduces mobility.
A confounder causes both high single motherhood rates in an area and reduced mobility.
Not having a dad reduces mobility.
A confounder causes not having a dad and reduces mobility.

The fundamental problem is that as we move right on the graph, a child is both raised in areas with more single motherhood and also is more likely to themselves be raised by a single mother.

The relationship in the second chart, on the other hand, can only be caused by (1) and (2). Therefore, the difference in the slopes is the combined effect of (3) and (4).

The slope of the first graph is 0.84 while the slope for the second is 0.70. This leaves a difference of 0.14. This is consistent with the theory that being raised without a dad causes a 14pp drop in childhood income. It is also consistent with the theory that confounders causes both a 14pp drop in childhood income and single motherhood.

I don't think we have any existing great ways to figure out which theory is correct here. We can be pretty sure confounders are a generally a problem, since studies that examine divorce and parental death frequently find quite different effects Mack Corak.

What all of this evidence suggests is that growing up in neighborhoods with high rates of single-motherhood has a much larger (negative) effect than growing up in a single-parent household. There are two interpretations here: either whether your father stuck around barely matters at all or neighbors matter a great deal.

Economic Connectivity

todo Social capital I: measurement and associations with economic mobility Social capital II: determinants of economic connectedness

Chetty, R., Jackson, M. O., Kuchler, T., Stroebel, J., Hendren, N., Fluegge, R. B., ... & Wernerfelt, N. (2022). Social capital I: measurement and associations with economic mobility. Nature, 608(7921), 108-121. https://doi.org/10.1038/s41586-022-04996-4 Chetty, R., Jackson, M. O., Kuchler, T., Stroebel, J., Hendren, N., Fluegge, R. B., ... & Wernerfelt, N. (2022). Social capital II: determinants of economic connectedness. Nature, 1-13. https://doi.org/10.1038/s41586-022-04997-3 Hymowitz, K. (2022). Raj Chetty’s Family Problem. Institute for Family Studies. https://ifstudies.org/blog/raj-chettys-family-problem Chetty, R., Hendren, N., Kline, P., & Saez, E. (2014). Where is the land of opportunity? The geography of intergenerational mobility in the United States. The Quarterly Journal of Economics, 129(4), 1553-1623. https://doi.org/10.1093/qje/qju022 Chetty, R., Friedman, J. N., Hendren, N., Jones, M. R., & Porter, S. R. (2018). The opportunity atlas: Mapping the childhood roots of social mobility (No. w25147). National Bureau of Economic Research. https://doi.org/10.3386/w25147 Pepin, J. R., Sayer, L. C., & Casper, L. M. (2018). Marital status and mothers’ time use: Childcare, housework, leisure, and sleep. Demography, 55(1), 107-133. https://doi.org/10.1007/s13524-018-0647-x Mack, K. Y. (2001). Childhood family disruptions and adult well-being: The differential effects of divorce and parental death. Death studies, 25(5), 419-443. https://doi.org/10.1080/074811801750257527 Corak, M. (2001). Death and divorce: The long-term consequences of parental loss on adolescents. Journal of Labor Economics, 19(3), 682-715. https://doi.org/10.1086/322078