Welcome Mat Effects for Dual Medicaid and Medicare Eligibles
To identify the effect of Medicaid expansions to working-age adults on seniors eligible for dual enrollment, we use Current Population Survey (CPS) data to examine Medicaid participation and general health among persons eligible for dual enrollment. Identification of causal effects comes through exogenous variation in coverage expansions to working-age adults across states and over time. We use data from the March supplements to the CPS from 2010 to 2015, a period of time beginning prior to ACA implementation and ending after the ACA was fully implemented. We examine the effect of early Medicaid expansions, implemented in 2010 and 2011, as well as expansions that occurred after January 1, 2014, when the ACA was fully implemented. As of November 2015, 30 states and Washington, DC had adopted the Medicaid expansion. We construct a sample of respondents aged 65 and older and eligible for Medicaid, where eligibility is based on having income below the federal poverty level, following Pezzin and Kasper (2002) and Ungaro and Federman (2009). We estimate difference-in-difference models of Medicaid program participation where the key explanatory variable will be an indicator variable that takes a value of 1 in the states that expanded Medicaid during the years that the Medicaid expansion was in effect, and 0 otherwise. We control for a rich set of individual and household traits including age, sex, race/ethnicity, marital status, education, income, urban residence, plus time-varying state-level characteristics such as Medicaid managed care penetration and unemployment rate, and state and year fixed effects. Our results have important implications for the complex and high-cost population of those eligible for dual enrollment, a large fraction of whom do not receive benefits that may improve health.