Toxic Truth: Lead And Fertility

Using US county-level data on lead in air for 1978-88, this paper provides the first causal evidence on the effects of airborne lead exposure on the general fertility rate and the completed fertility rate in the broad population. Instrumental variable estimates show an increase in fertility implied by the average observed decrease in airborne lead of about 6% of mean fertility. To explore the current relevance of our findings, we estimate the effect of lead historically accumulated in topsoil on fertility in the 2000s. The results suggest that lead may continue to impair fertility today, both in the United States and in other countries that have significant amounts of lead in topsoil.