Did the Medicaid expansions for children displace private insurance? An analysis using the SIPP

Using data from the 1990 panel of the Survey of Income and Program Participation (SIPP), we address the question: Did the Medicaid expansions for children cause declines in private coverage? We use a multivariate approach that attributes a displacement effect to declines in private coverage for children targeted by the Medicaid expansions exceeding declines for a comparison group of older low-income children. We find that 23% of the movement from private coverage to Medicaid due to the expansions was attributable to displacement. There is no evidence of displacement among those starting uninsured, leading to an overall displacement effect of 4%.