Title: Educational Inequality, Educational Expansion, and Intergenerational Income Persistence in the United States
Abstract: How has intergenerational income persistence remained stable in the US while education-based inequalities have grown? The children of high-income (low-income) parents tend to become high-income (low-income) adults. This intergenerational income persistence partly reflects education-based inequalities. High-income parents are more likely than low-income parents to raise highly educated children; highly educated children, in turn, typically enjoy higher incomes as adults than their less-educated peers. Over recent decades in the US, these education-based inequalities grew. Scholars thus predicted that intergenerational income persistence would increase. Yet previous research suggests that it did not. We address this puzzle using data from the National Longitudinal Surveys of Youth. Three findings emerge. First, educational expansion (more people completing college, whatever their parents' income) reduced intergenerational income persistence. Education helped low-income children become high-income adults---disrupting intergenerational persistence---in addition to helping high-income children become high-income adults. Second, growing education-based inequalities increased intergenerational income persistence much more than educational expansion reduced it. Changes in education furthered the replication of advantages more than they promoted mobility. Third, intergenerational income persistence remained stable despite growing education-based inequalities because of two countervailing forces: not only educational expansion, but also declining income predictability within education groups. New methodological tools underlie these findings, tools which quantify, for the first time, education's dual roles in income persistence.