Did the Affordable Care Act Save Lives?

The Institute for Research on Poverty hosts seminars on the UW-Madison campus most Thursdays during the academic year. These presentations are free and open to the public. Room 8417.

media release: Speaker: Anuj Gangopadhyaya, assistant professor, Department of Economics, Loyola University Chicago

Whether health insurance saves lives remains contested, and recent studies exploiting the Affordable Care Act’s (ACA) Medicaid expansions have reported sizable mortality reductions without obtaining direct estimates of the effect of coverage itself. We use the 2010 to 2013 National Health Interview Survey linked to the National Death Index through 2019 to study the effect of the ACA on the quarterly hazard rate of dying among adults aged 40 to 58, classifying individuals by their insurance status prior to the ACA so that the previously uninsured, who were highly treated, are compared to the previously insured, who were largely unaffected. A difference-in-differences design identifies the national effect of the ACA, which includes the Marketplace and the Medicaid woodwork effect, and a difference-in-difference-in-differences design that adds regional variation in Medicaid expansion identifies the marginal effect of the expansions. We find that estimates relying solely on geographic variation in expansion imply large mortality reductions, but these are driven entirely by the insured comparison group, for whom there is no plausible causal mechanism, indicating substantial confounding between expansion status and determinants of mortality unrelated to the policy. Once baseline insurance status is used to isolate exposure, the incremental effect of the Medicaid expansions on the mortality of the previously uninsured is close to zero, and what modest beneficial effect we observe is attributable to the national component of the ACA.