Estimating the Moral Hazard Effects of Health Insurance:Based on Micro Data
利用中国城镇职工医疗保险改革作为准实验，基于微观数据发现改革通过引入成本分担有效控制了道德风险，使参保者门诊费用下降28.6%-30.6%。
This paper employs the Urban Employment Medical Insurance(UEMI) reform as quasi-experiment to study the moral hazard effects of the health insurance based on the individual-level medical expenditure data from Chinese Health and Nutrition Survey(CHNS).Using the sample selection model and the difference-indifference estimator where the uninsured people serve as the control group,we find that cost sharing introduced by the health insurance reform substantially control moral hazard.After the reform,people with UEMI would not change their probabilities of seeing doctors but decrease the outpatient expenses by 28.6-30.6 percent.Two placebo tests confirm the robustness of the findings.Therefore,this paper concludes that the UEMI reform reduce the unreasonable medical expenditure by incorporating the demand side incentive.