Early lead exposure and outcomes in adulthood

We exploit the phase-out of leaded gasoline to isolate the impact of early childhood lead exposure on outcomes in adulthood. By combining administrative data on school performance, high school graduation, crime, earnings, and cognitive and non-cognitive skills with a novel measure of lead exposure, we follow 800,000 children from birth into adulthood. We find that reduced lead exposure improves the adult outcomes, particularly among boys. Below certain thresholds, the relationship becomes much weaker. Non-cognitive traits (externalizing behavior, conscientiousness, and neuroti­cism) follow a similar non-linear dose‑response pattern and seem to be the key mediators between early lead exposure and adult outcomes.