The Private Provision of Public Services: Evidence from Random Assignment in Medicaid
American Economic Review · 2022 · Danil Agafiev Macambira、Michael Geruso、Anthony Lollo、Chima D. Ndumele、Jacob Wallace
中文摘要
本文考察美国社会医疗保险私有化的影响。我们在医疗补助计划的背景下研究这一问题：该计划是美国规模最大的医疗保险项目，也是全国规模最大的家计调查型项目，为9000多万低收入家庭和残障人士提供服务。我们利用一项自然实验，其中近10万名医疗补助参保者被随机分配至州政府管理的按服务付费体系或私人管理式医疗计划，发现被分配至管理式医疗计划的参保者，其支出低近10%。这些节省主要集中在处方药方面：我们表明，事先授权是这些计划用来减少过度使用、并在不降低质量的前提下促使参保者转向低成本替代药物的关键机制。这与私有化对医疗服务福利的影响不同——在医疗服务福利方面，私人计划降低了服务质量、给消费者带来了更多困扰，却并未实现支出节省。与本文研究结果所隐含的高效公私服务分工相反，医疗补助计划历来倾向于由公共部门提供处方药，而将医疗服务外包给私人部门。
Abstract
This paper examines the effects of privatizing social health insurance in the United States. We study this question in the context of the Medicaid program, the largest health insurer in the US and the largest means-tested program in the nation -serving over 90 million low-income families and individuals with disabilities. Exploiting a natural experiment wherein nearly 100,000 Medicaid enrollees were randomly assigned between a state-administered fee-for-service system and private managed care, we find that spending was nearly 10% lower for enrollees assigned to managed care plans. These savings were concentrated in prescription drugs, where we show that prior authorization was the key mechanism plans used to reduce overuse and encourage substitution to lower-cost alternatives without reducing quality. This was distinct from the effects of privatization on medical benefits, where private plans lowered quality and abraded consumers without achieving savings. In contrast to what our findings imply for an efficient public-private division of services, Medicaid has historically favored the public provision of prescription drugs and private outsourcing of medical care.