Sociology
The Demography of Intergenerational Mobility and the Persistence of Class
Quick fact
Across many Western countries, about half of the income advantage (or disadvantage) of parents is passed on to their children. In countries like Denmark, this 'intergenerational elasticity' is around 0.15, while in the US it is close to 0.5, meaning class persistence is about three times stronger in the US.
Why this is interesting
You might assume that in a growing economy, children naturally do better than their parents. But do they? And if not, why does class seem to stick to families across generations?
Read the full explanation
Understanding The Demography of Intergenerational Mobility and the Persistence of Class
Think of a ladder: each rung is a social class. Intergenerational mobility asks how likely a child is to climb to a higher rung than their parents, or fall to a lower one. If the ladder is sticky, children tend to stay on their parents' rung—this is class persistence. Now, add demography: different families have different numbers of children. A higher-class family with few children can concentrate resources (education, connections, wealth) on each child, making it easier for those children to stay in the same class. A lower-class family with many children must divide limited resources, making upward mobility harder. Also, population composition matters: if a society has a large cohort of young people from large families, mobility patterns might differ from an aging society where small families are common. So, demography shapes the opportunities and constraints that produce mobility or persistence.
A deeper explanation
The mechanism is a cycle of resource transmission and demographic behavior. Families pass on not just wealth but also cultural capital (values, skills) and social networks. Higher-class families tend to have fewer children (lower fertility), which increases investment per child. Lower-class families historically have higher fertility, spreading resources thinner. This demographic difference reinforces class boundaries. Additionally, mortality and health: higher-class individuals live longer, giving them more time to pass advantages. Cohort replacement: as older generations die and new ones enter the workforce, if mobility patterns change with each cohort, the overall mobility rate shifts. Class persistence is not just about individual effort; it's a population-level outcome driven by demographic forces. Understanding this helps explain why inequality persists even when economies grow, and why policies targeting family size or education can affect mobility.