《保险研究》20251203-《激励相容原理下补充医疗保险最优决策研究——以惠民保为例》（马冰、贺如意、王吉元、周桦）

［摘   要］本文提出了一个包含多个决策主体的健康风险模型，假设医疗保险市场由基本医疗保险、大病保险以及以惠民保为代表的补充医疗保险构成，决策主体包括政府、保险公司和个体，研究了各个主体应如何决策以实现社会福利最大化。结果表明，如果政府制定适当的基本医保报销比例，保险公司针对高风险和低风险个体分别设定相应的惠民保自付比例，那么购买惠民保对个体而言是福利最大化选择，惠民保市场的逆选择问题也能得到有效控制。在基准模型的参数设定下，最优的基本医保报销比例为42.3%，低风险群体与高风险群体自付金额的比值应在1.3~1.58的区间内。敏感性分析显示：政府提高医疗卫生财政预算可以有效降低逆选择效应；个体的收入水平会影响其对于自付比例的容忍度，风险类型相同的情况下，收入越高，个体对于自付比例的容忍度越低；个体间收入水平差距加大将通过影响个体医疗保健预算增加惠民保市场失灵的风险，且惠民保市场对低收入个体的收入变化更加敏感。

［关键词］基本医疗保险；惠民保；激励相容原理；逆选择

［基金项目］本文获教育部人文社会科学重点研究基地项目(22JJD790092)资助。

［作者简介］马冰，中央财经大学保险学院副教授；贺如意，中央财经大学保险学院硕士研究生；王吉元，中央财经大学保险学院副教授；周桦（通讯作者），中央财经大学保险学院教授。

Optimal Design of Supplementary Medical Insurance under Incentive Compatibility—A Study of Huiminbao

MA Bing，HE Ru-yi，WANG Ji-yuan，ZHOU Hua

Abstract：This paper proposes a health risk model involving multiple decision-makers.We assume the medical insurance market is composed of basic medical insurance (BMI)，major medical expense insurance，and supplementary medical insurance represented by Huiminbao.The decision-makers include the government，insurance companies，and individuals.This study investigates how each entity should make decisions to maximize overall social welfare.The results indicate that social welfare is maximized and the purchase of Huiminbao is a welfare-maximizing choice for individuals when the government sets an appropriate BMI reimbursement ratio，and insurance companies set corresponding Huiminbao deductible ratios for high-risk and low-risk individuals.Furthermore，this dual-mechanism effectively controls the adverse selection problem in the Huiminbao market.Under the benchmark model parameters，the optimal BMI reimbursement ratio is 42.3%，and the ratio of deductibles for low-risk groups to high-risk groups should be within the range of 1.3 to 1.58.The sensitivity analysis further reveals the following key findings.Increased government fiscal budget for healthcare can effectively mitigate the adverse selection effect;individual income levels influence the tolerance for deductible ratios，and for the same risk type，higher-income individuals exhibit a lower tolerance for the deductible ratio;increased income disparity among individuals，by affecting individual healthcare budgets，raises the risk of Huiminbao market failure;crucially，the Huiminbao market is more sensitive to income changes among low-income individuals.

Key words：basic medical insurance;Huiminbao;incentive compatibility;adverse selection