The Impact of WIC on Infant's Immunizations and Healthcare Utilization in the First Year of Life

Abstract

We investigate how prenatal participation in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) impacts health care utilization and immunizations within the first year of an infant’s life. We utilize unique, comprehensive South Carolina Medicaid claims data in conjunction with birth certificates data for births from 2004-2012. We employ two methods to account for potentially non-random WIC participation: maternal fixed effects and propensity score matching. Both sets of estimates suggest that WIC participation broadly increases future preventive health care usage, as measured by well child visits and vaccinations, and the use of care in an emergency room. While the propensity score matching estimates suggest that WIC participation increases the probability of an infant requiring inpatient care, both sets of estimates show that WIC participation decreases the average number of days an infant spends in the hospital within their first year of life which may be associated with substantial reductions in health care expenditures.