Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We study how lead exposure impacts learning in elementary school using a natural experiment where a national automotive racing organization switched from leaded to unleaded fuel. Increased lead exposure harms academic performance, shifting the entire performance distribution, and negatively impacting both younger and older children. For a given total quantity of exposure, the marginal impacts of lead appear greater when spread over more years. The average treated student loses $5,200 of future income in present-value terms. This effect is similar to reducing class size by three students or increasing school spending per pupil by $750.