The Private Provision of Public Services: Evidence from Random Assignment in Medicaid

This paper examines the effects of privatizing social health insurance.

This paper examines the effects of privatizing social health insurance. We exploit a natural experiment in Medicaid, wherein nearly 100,000 enrollees were randomly assigned between a publicly operated fee-for-service system and private managed care. Managed care reduced costs by 5.6 percent via cost-effective substitutions among prescription drugs and via lower prices for outpatient services. We present evidence that pharmacy utilization management was the key mechanism reducing overuse and encouraging substitution to lower-cost drugs without decreasing observed quality. In contrast, privatizing medical benefits led to only modest savings and was associated with decreased health care quality and consumer satisfaction. (JEL G22, H41, I13, I18, I38)