Original title: Identification and Estimation of Intergenerational Income Mobility Measures
Alejandro Puerta-Cuartas · September 2026
Measuring how wealth passes from parents to children is difficult. Researchers usually only see snapshots of a person's earnings at certain ages instead of their whole lifetime. Averaging these snapshots causes life-cycle biasThe error that comes from measuring income at one point in life, when earnings naturally rise and fall with age., which distorts results. To solve this, the author treated missing years of earnings as a missing data problem. The new method uses observable personal details and machine learning to fill in the missing information and remove the bias. Applying this system to United States data showed that parents' income shapes their children's earnings much more than earlier tools suggested. It produced mobility measures between 0.6 and 0.7, averaging 0.64. This proves that family economic status persists far more across generations than standard models showed.
You are betting on which of two kids will be taller as adults, but you only meet each once: one at age 9, the other at 14. The 14-year-old looks tall now, but the 9-year-old may still have a growth spurt coming, so a single meeting tells you little about the final heights. In this paper, researchers compare families' economic status the same way: they only see income at a few ages, not across whole careers. They correct for that by using observable characteristics to fill in the missing years, just as you might use family height patterns to guess adult height.
If the new estimates are right, the U.S. is less economically mobile than standard statistics suggest. That changes how we measure opportunity and whether policies aimed at improving mobility are working. Anyone comparing mobility across countries or time could be relying on biased numbers.
The method relies on missing-at-random and testable independence assumptions; if they fail, the estimates could still be biased. The empirical results come from one U.S. survey, the PSID, and cover only birth cohorts 1954–1977, so they may not generalize to other countries, younger cohorts, or different mobility measures. The abstract does not report sensitivity analyses or how robust the findings are to alternative assumptions.
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Identification and Estimation of Intergenerational Income Mobility Measures — Alejandro Puerta-Cuartas
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.