How Robust are Estimates of Intergenerational Income Mobility?

Rising inequalities in rich countries have led to concerns that the economic ladder is getting harder to climb. It is well established that intergenerational income mobility is lower in countries with high inequality, but research on trends in mobility finds conflicting results. Motivated by this uncertainty, we ask: how important are choices of specification for levels and trends in intergenerational income associations? We use Swedish data on cohorts born 1958–1977 and their parents. Varying how, when and for whom income is measured, we estimate 1,658,880 different associations (82,944 specifications across 20 cohorts). Our results reveal that model choice is an underrecognized source of variation in intergenerational mobility research. The most consistent contributor to trends is the advancement of women in the labor market, which leads to increased persistence in women’s earnings and the family income of both men and women. Depending on specification, it is possible to conclude that income mobility is increasing, decreasing, or remaining flat. Despite variability, our results are broadly consistent with the received view that the level of mobility in Sweden is high in a comparative perspective.