Description
Adjusting for observable confounds and publication bias yields a benchmark estimate of a 0.12 standard deviation reduction in learning per natural log unit of blood lead. As all estimates are non-experimental, we present evidence on the likely magnitude of unobserved confounding, and summarize results from a smaller set of natural experiments. Our benchmark estimate accounts for over a fifth of the gap in learning outcomes between rich and poor countries, and implies moderatelearning gains from targeted interventions for highly exposed groups (≈ 0.1 standard deviations) and modest learning gains (< 0.05 standard deviations) from broader public health campaigns.
