More on fracking and social mobility

In a post last week, I noted that children who grow up in commuting zones (CZs) located in fracking states tend to have high rates of upward income mobility, as measured by Chetty et al.'s new estimates of the causal impact of growing up in different CZs. A caveat was that this tendency appeared to be almost entirely accounted for by a single fracking state, namely North Dakota. Here I provide further evidence that upward mobility tends to be higher in areas with fracking. 

In addition to their main estimates of the causal impact of growing up in difference CZs, Chetty et al. calculated separate estimates for boys and girls. Since fracking is an overwhelmingly male-dominated industry, CZs located in fracking states should be overrepresented among those with the largest causal impacts for boys, but not among those with the largest causal impacts for girls. The chart below, which is based on the same methodology as before, plots the percentage of CZs at a given rank or higher located in fracking states against rank on individual income causal impact, separately for boys and girls. (Estimates of household income causal impact were not considered as these represent the combined income of husband and wife.)

Once again, 27% of CZs are located in fracking states. Importantly, the line for boys is substantially higher than the line for girls, especially on the left-hand side. Moreover, the line for boys is strictly above 27%, whereas the line for girls is below this percentage from rank 8 onwards. (The line for girls begins at 100% since the highest-ranked CZ happens to be located in fracking state). This indicates that, as expected, CZs located in fracking states are overrepresented among those with the largest causal impacts for boys, but are underrepresented among those with the largest causal impacts for girls. 

For boys: 48% of the top 50 CZs are located in fracking states, 65% of the top 20 are located in fracking states, and 90% of the top 10 are located in fracking states. For girls, by contrast: 16% of the top 50 CZs are located in fracking states, 15% of the top 20 are located in fracking states, and 20% of the top 10 are located in fracking states. And unlike last time, North Dakota is not the only fracking state well-represented at the top of the boys' ranking: CZs located in Texas and Wyoming also preponderate there.