Nber Working Paper Series Estimates of Crowd-out from a Public Health Insurance Expansion Using Administrative Data

We use a combination of administrative and survey data to estimate the fraction of individuals newly enrolled in public health coverage (Wisconsin’s combined Medicaid and CHIP program) that had access to private, employer-sponsored health insurance at the time of their enrollment and the fraction that dropped this coverage. We estimate that after expansion of eligibility for public coverage, approximately 20% of new enrollees had access to private health insurance at the time of enrollment and that only 8% dropped this coverage (with the remaining 12% having both private and public coverage). We also identify an “upper bound” estimate, which suggests that the percentage of new enrollees with private insurance coverage at the time of enrollment is, at most, 27%. These estimates of crowd-out are relatively low compared with estimates from the literature based on Medicaid and CHIP expansions, although based both on different data and on a different method. Laura Dague Department of Economics University of Wisconsin-Madison 1180 Observatory Drive Madison, WI 53706-1393 [email protected] Thomas DeLeire La Follette School of Public Affairs University of Wisconsin-Madison 1225 Observatory Drive Madison, WI 53706 and NBER [email protected] Donna Friedsam UW Population Health Institute University of Wisconsin-Madison 610 Walnut Street Madison, WI 53726 [email protected] Daphne Kuo UW Population Health Institute University of Wisconsin-Madison 610 Walnut Street Madison, WI 53726 [email protected] Lindsey Leininger Chapin Hall at the University of Chicago 1313 E. 60th Street Chicago, IL 60637 [email protected] Sarah Meier Department of Population Health Sciences 610 Walnut Street Madison, WI 53726 [email protected]