Healthcare access and human capital: evidence from Medicaid expansion

This paper investigates whether healthcare access affects educational achievement, exploiting the staggered ACA Medicaid expansion. Using county-level panel data on ACT scores, insurance coverage, and health indicators for 2012–2024, I find that Medicaid expansion raised county-level ACT composite scores by 0.50 to 0.85 points (about 0.22 standard deviations in the controlled specification). A Callaway and Sant’anna heterogeneity-robust estimator yields a simple aggregated ATT of 0.79, indicating the result is not an artefact of forbidden comparisons, and an event study is consistent with parallel pre-trends, with effects building to approximately 1.3 points by 6 years that I read as a suggestive long-run trajectory. The estimate attenuates and loses significance under within-region and within-division comparison and under relative-magnitude pre-trend violations, so I interpret it as suggestive of a causal effect under the design’s identifying assumptions rather than a firmly established magnitude. A supplementary instrumental-variables specification is consistent in sign but imprecise. A selection test does not detect changes in test participation, and channel analysis finds that observable health and economic indicators do not meaningfully mediate the effect, leaving the mechanism an open question for future research with individual-level data.