效率与公平统一的医疗保险水平——来自城乡居民医疗保险制度整合的证据

The Medical Insurance Based on Efficiency and Equity:Evidence from the Integration of the National Basic Medical Insurance Program for Urban and Rural Residents

现有最优医保的研究主要以效率为目标,平衡社会保险的消费平滑和道德风险两方面的目标。本文加入医疗服务利用的政策目标,拓展了最优保险理论,利用城乡居民医疗制度整合的准自然实验,采用充分统计量方法,考虑了城乡医疗服务利用的差距,估计了最优医疗保险水平。研究发现,若只考虑效率目标,最优医保报销比例约为44%左右;若同时考虑效率与基本医疗服务利用目标,则最优医保报销比例可提高到70%左右。研究还发现,城乡医保整合显著提高了农民的住院概率和住院费用,医疗服务利用的价格弹性约为-0.45;医疗保险具有明显的消费平滑作用,住院报销比例每提高10个百分点,会使得农村家庭因患病而挤出的人均消费减少3.2%。文章还进一步测算了最优医保水平下所需的政府补贴和对个体福利的改善。本研究为进一步提升城乡医保待遇提供了依据。

The optimal social insurance theory highlights that to achieve maximum efficiency,there is a tradeoff between welfare losses due to moral hazard and welfare gains from risk protection.We add to these models that equity in health care needs to be considered in designing public health insurance.By equity,we mean that the basic health care is related only to health needs and not to socioeconomic status.In China,due to low incomes,rural households tend to delay or give up seeking medical care,leading to an urban-rural health care imbalance.Since rural households are more sensitive to healthcare costs,a higher reimbursement rate in health insurance can boost their demands and promote the urban-rural health care equity.This paper extends the optimal social insurance theory by considering the urban-rural health care equity.We calculate the optimal health insurance of rural households using the sufficient statistics approach.In recent years,China has integrated the basic medical insurance for urban residents and the new rural cooperative medical system into a basic medical insurance for urban and rural residents,and the reimbursement rate for rural residents has been greatly increased.We first estimate the price elasticity of health care using a quasi-natural experiment in China in which rural and urban social health insurance programs are integrated.We find that the integration significantly raises inpatient probability and inpatient expenses of rural residents.We estimate a health care price elasticity of-0.45,which is higher than that in advanced economies,but closer to other estimates in the context of China.We also find that health insurance has a significant consumption-smoothing effect among rural households.A 10-percentage-point increase in inpatient reimbursement rate offsets the drop in households’per capita non-medical consumption upon illness by 3.2%.We then calculate the optimal health insurance for rural households using the method of sufficient statistics.Under a pure efficiency goal,the optimal reimbursement rate is about 44%.However,with this rate,the rural health care expenditures would be substantially lower than the urban health care expenditures because rural households are more likely to be constrained in terms of liquidity.The notion of equity requires rural and urban health care expenditures be comparable regardless of their income conditions.We thus use the urban-rural income gap as a proxy for rural household liquidity constraint and calculate the optimal insurance in a model where all three factors,namely,moral hazard,consumption smoothing,and liquidity constraints,are considered.This model yields an optimal reimbursement rate of 70%,significantly higher than that of the traditional model where equity is ignored.In addition,we calculate the required government subsidies and find that the health insurance that combines efficiency and equity improves social welfare.This paper contributes to existing literature in three ways.Firstly,we extend the optimal health care insurance theory.In developing countries where the basic medical demand is still not met,public health insurance plays an important role in promoting equity in health and health care.Therefore,it is necessary to consider equity on the basis of the classical model.Secondly,this paper contributes to a strand of literature that examines the effect of urban-rural medical insurance integration.Existing literature has evaluated this effect on health care utilization and the narrowing of urban-rural gap separately.Still,a comprehensive evaluation is needed.Thirdly,we calculate the optimal health insurance reimbursement rate using a sufficient statistics approach.We estimate the moral hazard and consumption smoothing effects of health insurance and apply the sufficient statistics approach to the Chinese context.This paper has the following policy implications.First,the reimbursement rate of public health insurance needs to be further improved.The government should further adjust the covered drug list,comprehensively considering various factors such as clinical needs,fund affordability,and the ability of pharmaceutical companies to reduce drug prices.Second,the government can reduce medical expenses through a centralized drug procurement policy,reform of medical insurance payment methods,and other measures,thereby increasing the proportion of financial subsidies in the total medical expenses.