Weighing down the future: long-term effects of childhood obesity on intergenerational mobility

Abstract

Amidst declining intergenerational mobility in the United States, this paper identifies a critical and understudied barrier: childhood health. Using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) linked to neighborhood opportunity measures from the Opportunity Atlas, we estimate the long-term economic consequences of childhood obesity. To address endogeneity, we construct a novel genetic instrumental variable for body mass index (BMI) that removes confounding genetic variation related to intelligence, cognitive function, and educational attainment, thereby mitigating concerns of horizontal pleiotropy. We find that compared to their normal-weight peers, obese children experience substantially less upward income mobility, ending up approximately 20 percentile points lower than their parents in the adult income distribution and being less likely to live in higher-opportunity neighborhoods. This health-based penalty is driven by lower educational attainment, persistent health problems, and adverse occupational sorting. Our results point to an income–health feedback loop that can reinforce poverty across generations, highlighting the policy importance of childhood health interventions to improve both health and economic mobility.