SCHIP expansion and parental coverage: an evaluation of Wisconsin's BadgerCare

The Wisconsin BadgerCare program, which became operational in July 1999, expanded public health insurance eligibility to both parents and children in families with incomes below 185% of the U.S. poverty line (200% for those already enrolled). This eligibility expansion was part of a federal initiative known as the State Children's Health Insurance Program (SCHIP). Wisconsin was one of only four states that initially expanded coverage to parents of eligible children. In this paper, we attempt to answer the following question: To what extent does a public program with the characteristics of Wisconsin's BadgerCare program reduce the proportion of the low-income adult population without health care coverage? Using a coordinated set of administrative databases, we track three cohorts of mother-only families: those who were receiving cash assistance under the Wisconsin AFDC and TANF programs in September 1995, 1997, and 1999, and who subsequently left welfare. We follow these 19,201 "welfare leaver" families on a quarterly basis for up to 25 quarters, from 2 years before they left welfare through the end of 2001, making it possible to use the labor market information and welfare history of the women in analyzing outcomes. We apply multiple methods to address the policy evaluation question, including probit, random effects, and two difference-in-difference strategies, and compare the results across methods. All of our estimates indicate that BadgerCare substantially increased public health care coverage for mother-only families leaving welfare. Our best estimate is that BadgerCare increased the public health care coverage of all adult leavers by about 17-25% points.