Overview
John N. Friedman is a professor of economics at Brown University and a research associate at NBER. His research uses large-scale administrative tax and government records to study income inequality, intergenerational mobility, and the determinants of disability insurance take-up. He is a co-author of the foundational Chetty, Friedman, Hendren, and Saez (2014) study of geographic intergenerational income mobility, and lead author of Friedman et al. (2016, 2018) on long-run and geographic drivers of young adult DI receipt.
Key Contributions / Features
- Friedman et al. (2016) — "Long-Run Drivers of Disability Insurance Rates": Establishes three facts using IRS admin tax data linking 38.4M young adults (born 1980–1990) to their parents: (1) DI hazard at ages 24–34 is 4.8× higher for the bottom parental income percentile than the top; (2) geographic variation in DI is almost entirely concentrated among poor children; (3) ~50% of place differences are causal (Chetty-Hendren movers design). First paper to document the "good places paradox": high-DI CZs for poor children score better on inequality, segregation, schools, and social capital.
- Friedman et al. (2018) — "Explaining Geographic Differences in Young Disability Insurance Rates": With Kellogg, Lurie, and Mogstad. Extends the 2016 analysis: adds cyclicality (DI entry 3× more volatile for poor children), separates sorting from causal mechanisms via signal correlations from mover estimates, consolidates characteristics into 8 CFA factors, and directly compares DI take-up to income mobility. Shows education and taxes are causal DI predictors while segregation and inequality are sorting artifacts.
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