The Effects of Introducing Mixed Payment Systems for Physicians: Experimental Evidence
通过实验室实验，研究了按项目付费、按人头付费和混合支付对医生服务量的影响，发现混合支付能减少偏离患者最优治疗的程度，且利他主义可部分缓解代理问题。
Mixed payment systems have become a prominent alternative to paying physicians through fee-for-service and capitation. While theory shows mixed payment systems to be superior, causal effects on physicians' behavior when introducing mixed systems are not well understood empirically. We systematically analyze the influence of fee-for-service, capitation, and mixed payment systems on physicians' service provision. In a controlled laboratory setting, we implement an exogenous variation of the payment method. Medical and non-medical students in the role of physicians in the lab (N = 213) choose quantities of medical services affecting patients' health outside the lab. Behavioral data reveal significant overprovision of medical services under fee-for-service and significant underprovision under capitation, although less than predicted when assuming profit maximization. Introducing mixed payment systems significantly reduces deviations from patient-optimal treatment. Although medical students tend to be more patient regarding, our results hold for both medical and non-medical students. Responses to incentive systems can be explained by a behavioral model capturing individual altruism. In particular, we find support that altruism plays a role in service provision and can partially mitigate agency problems, but altruism is heterogeneous in the population. Copyright © 2015 John Wiley & Sons, Ltd.