Class 24: Medicaid Expansion and Uninsurance

The goal of this module is to understand difference-in-differences as a causal identification strategy. We’ll do this in the context of Medicaid expansion and its effect on uninsurance.


  • Understand some of the large changes introduced by the Affordable Care Act
  • Explain what we mean by “Medicaid expansion”
  • Understand the ACS data and how to access the data in R


  • Review homework 4 and RD in practice
  • Import ACS data via API in R
  • Summarize insurance status over time


Angrist, J., and J. Pischke. 2009. Mostly Harmless Econometrics. Princeton, NJ: Princeton University Press.
Courtemanche, Charles, James Marton, Benjamin Ukert, Aaron Yelowitz, and Daniela Zapata. 2017. “Early Impacts of the Affordable Care Act on Health Insurance Coverage in Medicaid Expansion and Non-Expansion States.” Journal of Policy Analysis and Management 36 (1): 178–210.
Obama, Barack. 2016. “United States Health Care Reform: Progress to Date and Next Steps.” Jama 316 (5): 525–32.