“Family structure doesn’t really matter—at least when it comes to explaining the stark racial gap in upward mobility between black and white boys.” This was one popular takeaway from the latest blockbuster study on economic opportunity released this week from Stanford economist Raj Chetty and his colleagues Nathaniel Hendren, Maggie Jones, and Sonya Porter. In the study, Chetty et al. found that black boys are much less likely to realize the American Dream—economically speaking—as they move into adulthood, compared to white boys; by contrast, black girls are much more likely to do well economically as young adults, compared to white girls.