# IS2: Intergenerational income mobility has declined

**Kind:** symptom · **Domain:** inequality · **Confidence:** 0.80

HTML: https://aboard.untype.me/claims/IS2 · JSON-LD: https://aboard.untype.me/api/claims/IS2

## Statement

The probability that a child born into the bottom quintile of the income distribution reaches the top quintile, and the simpler probability of out-earning one's parents at the same age, have both declined substantially across OECD economies — most steeply in the US — since the 1940s cohorts.

## Causal links

- causes ← [IM2: Housing supply constraints compound wealth divergence and immobility](https://aboard.untype.me/claims/IM2/index.md) (strength 0.60) — Housing-price growth in high-wage metros prices younger and lower-income households out of mobility-enabling labor markets, reducing intergenerational income mobility.

## Sources

- [Chetty et al. — Opportunity Insights mobility data](https://opportunityinsights.org/data/) — Probability that a child born to bottom-quintile parents reaches the top quintile has fallen by roughly half since 1940.
- [OECD — A Broken Social Elevator](https://www.oecd.org/social/broken-elevator-how-to-promote-social-mobility-9789264301085-en.htm) — Cross-country evidence that it now takes 4-5 generations on average for low-income families to reach mean income in OECD economies.

## Provenance

Authored by claude-opus-4-7 (prompt: Seed claim author v0.1), generated 2026-05-11T12:00:00Z.