How did medicaid expansions affect labor supply and welfare enrollment? Evidence from the early 2000s

In the early 2000s, Arizona, Maine, New Mexico, New York, Oregon, and Vermont expanded Medicaid to cover more low-income individuals, primarily childless adults. This change provides the researcher with an opportunity to analyze the effects of these expansions on labor supply and welfare enrollment. I use a large data set of 176 counties over 7 years, including 3 years of pre-expansion period, 1 year of implementation year, and 3 years of post-expansion period. Using a difference-in-differences approach, I find the most-affected counties had a 1.4 percentage-point more decline in labor force participation rate in comparison to other counties. Furthermore, I observe a 0.32 h decrease in average weekly hours and a 1.1 % increase in average weekly wages. This indicates labor supply was affected more than labor demand. I also observe a 0.49 % increase in Supplemental Nutrition Assistance Program (SNAP) enrollment after the Medicaid expansions. These results are robust to an alternative identification of the most-affected counties, inclusion of counties from comparison states, limiting the control group to only high-poverty counties from comparison states, exclusion of county-specific time trends, and different configuration of clustered errors. My findings provide early insights on the potential effects of new Medicaid expansions of the Affordable Care Act (ACA), since 82 % of those newly eligible are expected to be childless adults.