Supplemental Security Income, Medicaid, and Child Outcomes: Evidence from Birth Weight Eligibility Cut-Offs

The Supplemental Security Income (SSI) program provides means-tested income support to individuals with disabilities in the United States. In addition, infants born below certain low birth weight cut-offs are eligible for SSI regardless of family income. Between 1990 and 2010, the number of children receiving SSI benefits rose over 300%. Beyond income support, many SSI recipients also receive publicly-provided health insurance through state Medicaid programs; thirty-two states automatically enroll SSI recipients into their Medicaid programs. In this paper, we examine the relationship between SSI, Medicaid, and child outcomes. First, we employ a regression discontinuity approach and compare outcomes for infants born just under the SSI eligibility birth weight cut-offs to those for infants born just above the cut-offs. We show that SSI receipt is discontinuous using SSA administrative data and using National Health Interview Survey (NHIS) data. Next, we estimate the relationship between SSI eligibility and birth and early childhood outcomes using a wide variety of data sets including the Vital Statistics Natality Detail, the Early Childhood Longitudinal Study Birth Cohort, NHIS, and Healthcare Cost and Utilization Project. Last, since Medicaid policies produce variation in the access to Medicaid among SSI-eligible infants, we use a difference-in-difference model comparing infants around the SSI birth weight cut-offs, but who live in different states. First, we compare more generous self-enroll states with less generous self-enroll states to see whether the difference in Medicaid resources improves health. Second, we compare auto-enroll states with self-enroll states to see whether default enrolling leads to increased Medicaid enrollment, greater utilization of health services and better health. Our preliminary results suggest a statistically significant difference in SSI receipt between infants born just below and just above the eligibility cut-offs based on birth weight and gestational age, as well as positive effects of SSI receipt on certain child outcomes.