Social Insurance and Redistribution with Moral Hazard and Adverse Selection*

Rochet (1991) showed that with distortionary income taxes, social insurance is a desirable redistributive device when risk and ability are negatively correlated. This finding is re‐examined when ex post moral hazard and adverse selection are included, and under different informational assumptions. Individuals can take actions influencing the size of the loss in the event of accident (or ill health). Social insurance can be supplemented by private insurance, but private insurance markets are affected by both adverse selection and moral hazard. We study how equity and efficiency considerations should be traded off in choosing the optimal coverage of social insurance when those features are introduced. The case for social insurance is strongest when the government is well informed about household productivity.     

The impact of private hospital insurance on the utilization of hospital care in Australia

We use the Australian National Health Survey to estimate the impact of private hospital insurance on the propensity for hospitalization as a private patient. We account for the potential endogeneity of supplementary private hospital insurance purchases and calculate moral hazard based on a difference-of-means estimator. We decompose the moral hazard estimate into a diversion component that is due to an insurance-induced substitution away from public patient care towards private patient care, and an expansion component that measures a pure insurance-induced increase in the propensity to seek private patient care. Our results suggest that on average, private hospital insurance causes a sizable and significant increase in the likelihood of hospital admission as a private patient. However, there is little evidence of an expansion effect; the treatment effect of private hospital insurance on private patient care is driven almost entirely by the substitution away from public patient care towards private patient care. We discuss the implications for policies that aim to expand supplementary private insurance coverage for the purpose of reducing excess demand on the public healthcare system.     

Information Asymmetries and Risk Management in Healthcare Markets: The U.S. Affordable Care Act in Retrospect

This article critically examines the pertinent issues in ex ante and ex post moral hazard in healthcare markets, with the U.S. Affordable Care Act (ACA) as its focal point of inquiry. First, it compares the various types of information asymmetries resulting from the production, allocation, and utilization of health insurance. Second, it reviews the literature on adverse selection, moral hazard, and risk mitigation against which salient ACA reforms are analyzed. In contrasting conventional moral hazard from an alternative theory of welfare maximization, it suggests that healthcare (over)utilization cannot necessarily be considered wasteful, even if it ends up costing insurers more on a short-term basis. Costs and savings attributable to healthcare spending under the ACA will vary between the consumer, insurer, and regulator-subsidizer. Despite the ambiguities surrounding definitions of “health,” the challenge of containing inefficient moral hazard, and encouraging its desirable counterpart, lies in the tradeoffs that arise between consumer access to affordable and quality healthcare and the market competitiveness of health insurers. The new Trump administration will have to address these tradeoffs in repealing and replacing the ACA, particularly in light of escalating insurance premiums and deductibles, narrower provider networks, and technical implementation issues.     

Ex Post Welfare under Alternative Health Care Systems

The implications of a societal aversion to inequality for the optimal structure of the health care system are studied. The agents are assumed to be ex ante identical, but to differ ex post in the state of their health. Inequality aversion is introduced by postulating a strictly concave ex post social welfare function. It is shown that the optimal public health care system allocates health care differently than would private health insurance; specifically, people who are relatively unhealthy with and without treatment receive more health care, and people who are relatively healthy with and without treatment receive less health care. The aggregate quantity of health care under the optimal public health care system can be either greater or smaller than under private health care insurance. If the public health care system is optimally designed, allowing agents to purchase supplementary private health care insurance cannot raise social welfare and is likely to decrease it.     

OBESITY AND MORAL HAZARD IN DEMAND FOR VISITS TO PHYSICIANS

In this article, we use count data regression with sample selection to analyze the effects and degree of moral hazard in demand for visits to physicians among groups of individuals with similar body mass index (BMI). Our results suggest that the effect of moral hazard on the demand for visits to doctors is increasing in BMI for men and for overweight and obese women. Moral hazard is highest among overweight men. (JEL I11, C25)     

Unemployment Insurance under Moral Hazard and Limited Commitment: Public versus Private Provision

This paper analyzes a model of private unemployment insurance under limited commitment and a model of public unemployment insurance subject to moral hazard in an economy with a continuum of agents and an infinite time horizon. The dynamic and steady‐state properties of the optimum private unemployment insurance scheme are established. The interaction between public and private unemployment insurance schemes is examined. Examples are constructed to show that for some parameter values increased public insurance can reduce welfare by crowding out private insurance more than one‐to‐one and that for other parameter values a mix of both public and private insurance can be welfare maximizing.     

The determinants of the demand for private health insurance under Medicare

Since the introduction of Medicare in 1984, the proportion of the Australian population with private health insurance has declined considerably. Insurance for health care consumption is compulsory for the public health sector but optional for the private health sector. In this paper, we explore a number of important issues in the demand for private health insurance in Australia. The socio-economic variables which influence demand are examined using a binary logit model. A number of simulations are performed to highlight the influence and relative importance of various characteristics such as age, income, health status and geographical location on demand. A number of important policy issues in the private health insurance market are highlighted. First, evidence is provided of adverse selection in the private health insurance pool, second, the notion of the wealthy uninsured is refuted, and finally it is confirmed that there are significant interstate differences in the demand for private health insurance.     

A dynamic analysis of the demand for health insurance and health care

We find that asymmetric information is important for the uptake of supplementary private health insurance and health care utilization. We use dynamic panel data models to investigate the sources of asymmetric information and distinguish short-run selection effects into insurance from long-run selection effects. Short-run selection effects (i.e. responses to shocks) are adverse, but small in size. Also long-run effects driven by differences in, for example, preferences and risk aversion, are small. But we find some evidence for multidimensional asymmetric information. For example, mental health causes advantageous selection. Estimates of health care utilization models suggest that moral hazard is not important.     

中国居民医疗保险购买行为研究-基于商业健康保险的角度

本文通过健康保险市场供需双方行为分析,构建居民医疗保险购买行为模型,利用中国健康与营养调查数据(2000—2006),运用部分观测的二元Probit估计方法(Bivariate Probit with partial observability),从实证的角度分析商业健康保险市场中供需双方各自的风险选择行为,以及城乡地区居民对商业健康保险的潜在需求行为及其宏微观影响因素。本文发现:(1)城乡居民都存在显著的逆向选择行为;(2)城乡社会医疗保障对居民商业健康保险需求行为有显著的促进作用;(3)影响居民商业健康保险行为的其他因素还包括,个人的风险偏好和经济购买力。     

INSURANCE‐INDUCED MORAL HAZARD: A DYNAMIC MODEL OF WITHIN‐YEAR MEDICAL CARE DECISION MAKING UNDER UNCERTAINTY

This study quantifies the moral hazard effect of health insurance on medical expenditure by estimating a dynamic model of within‐year medical care consumption that allows for insurance selection, endogenous health transitions, and individual uncertainty about medical care prices in an environment where insurance has nonlinear cost‐sharing features. The results suggest that moral hazard accounts for 53.1%, on average, of total annual medical expenditure when insured. This estimate is significantly different, and generally larger, than that produced by an alternative model that is representative of the annual medical care decision‐making models commonly found in the literature.     

Private investment with social benefits under uncertainty: The dark side of public financing

We develop a game‐theoretic model of private–public contribution to a long‐term project with sequential actions and moral hazard. A private agent is one who is in charge of both the financial contribution and the management effort, these two actions entailing private costs and uncertain ex‐post private and social benefits. A public agent is one who decides the amount of public funding to this quasi‐public good, knowing that the size and the probability of attaining a surplus ex post depend on the private agent's effort. We consider four public‐funding scenarios: benefit‐sharing versus cost‐sharing crossed with ex‐ante versus ex‐interim government intervention. We test our theoretical predictions by means of an experiment that confirms the main result of the model: Cost‐sharing public intervention is more effective than benefit‐sharing in boosting private financial contribution to the project. Furthermore, when public intervention comes after private contribution ( ex‐interim government intervention), both public‐funding scenarios have a negative impact on the private management effort. In our model, the latter result is explained by the private agent's high degree of risk aversion. These results have policy implications for strategic investments with long‐term social consequences. In deciding the optimal timing and method of the contribution, governments should also consider the indirect effects on agents’ long‐term management efforts.     

A Revelation Mechanism for Soft Information under Moral Hazard

This paper constructs a revelation mechanism to address a problem of moral hazard under soft information. The agent alone observes the stochastic outcome of her action, which she reports to the principal. Therefore the principal also faces a problem of ex post adverse selection. Economically relevant restrictions induce constraints on the principal's choice of mechanism and the Revelation Principle fails to apply. Specifically, a direct mechanism induces some pooling, which does not replicate the allocation obtained using a larger message space. Pooling also weakens the ex ante incentives. The Revelation Principle is extended to obtain type separation. A better audit relaxes frictions.     

Private insurance subsidies and public health care markets: evidence from Canada

In this study I examine the effects of government subsidies to employer-provided health insurance on the decision to purchase insurance, and on utilization of publicly funded health services. Using unique variation in tax subsidies across Canadian provinces as an instrument, I estimate the effects of these subsidies on the demand for supplemental health insurance and their extended effects on the decision to use publicly-funded health services. My results show that government subsidies through tax exemptions have significant effects on the decision to purchase insurance. Furthermore, additional insurance policies lead to moral hazard in the use of publicly funded health services. JEL Classification: H2,H4, I1     

Moral hazard,insurance claims,and repeated insurance contracts

Abstract The paper develops a simple model of repeated automobile insurance contracts, providing a framework for analyzing changes in aggregate insurance data in periods of changes that affect driver incentives. Experience rating of premiums gives drivers an incentive to exert effort to avoid accidents (ex ante moral hazard), and an incentive to hide accidents (ex post moral hazard). The empirical analysis, using data from the competitive insurance markets in Ontario and Alberta over a period of major legislative changes in Ontario, suggests that much of the recent decline in accidents in Ontario was due to an increased incentive to hide accidents.     

Medical insurance with rank-dependent utility

Summary. A well-known result in the medical insurance literature is that zero co-insurance is never second-best for insurance contracts subject to moral hazard. We replace the usual expected utility assumption with a version of the rank-dependent utility (RDU) model that has greater experimental support. When consumers exhibit such preferences, we show that zero co-insurance may in fact be optimal, especially for low-risk consumers. Indeed, it is even possible that the first-best and second-best contracts are identical. In this case, there is no “market failure”, despite the informational asymmetry. We argue that these RDU results are in better accord with the empirical evidence from US health insurance markets. Received: February 26, 2001; revised version: October 4, 2002 RID="*" ID="*"The authors would particularly like to thank Simon Grant, John Quiggin, Peter Wakker and an anonymous referee for valuable comments and suggestions on earlier drafts. The paper has also benefitted from the input of seminar audiences at The Australian National University, University of Auckland, University of Melbourne and University of Sydney. Ryan also gratefully acknowledges the financial support of the ARC, through Grant number A000000055. Correspondence to:R. Vaithianathan     

Long‐term care policy with lazy rotten kids

This paper studies the determination of informal long‐term care (LTC) provided by children in a scenario which is somewhere in between perfect altruism and selfish exchanges. Parents are altruistic but children are purely selfish, and neither side can make credible commitments. The model is based on Becker's “rotten kid” specification except that it explicitly accounts for the sequence of decisions. In Becker's world, with a single good efficiency is achieved. We show that when family aid is introduced the outcome is likely to be inefficient. Still, the rotten kid mechanism is at work and ensures that a positive level of LTC is provided as long as the bequest motive is operative. We identify the inefficiencies by comparing the laissez‐faire (subgame perfect) equilibrium to the first‐best allocation. We first assume that families are identical ex ante and then consider the case where dynasties differ in wealth. We study how the provision of LTC can be improved by public policies. Interestingly, crowding out of private aid by public LTC is not a problem in this setting. With an operative bequest motive, public LTC will have no impact on private aid. More amazingly still, when the bequest motive is (initially) not operative, public insurance may even enhance the provision of informal aid.     

Endogenous Specialisation and Endogenous Principal-agent Relationship

The paper develops a general equilibrium model with endogenous principal-agent relationship within a framework of consumer-producer, economies of specialisation, and transaction costs. It is shown that if transaction efficiency is low, then autarky is chosen as the general equilibrium where no market and principal-agent relationship exists. As transaction efficiency is improved, the equilibrium level of division of labour increases, comparative advantage between ex ante identical individuals emerges from the division of labour, and the number of principal-agent relationships increases. The following features of the model distinguish it from other principal-agent models in the literature. The principal-agent relationships are not only endogenous, but also reciprocal between different specialists. In a general equilibrium environment, choice between pure pricing and contingent pricing is endogenised. In the paper, the implications of endogenous transaction costs caused by moral hazard for the equilibrium extent of the market and related degrees of market integration, production concentration, trade dependence, diversity of economic structure, and productivity are explored. The model predicts two interesting phenomena: a man might work harder for the market with moral hazard than working for himself in the absence of moral hazard; a market with moral hazard might be Pareto superior to autarky with no moral hazard.     

The Demand for Private Medical Insurance in the UK: A Cohort Analysis

This paper examines the determinants of the demand for private health insurance in the United Kingdom from 1978 to 1996 using a pseudo-cohort panel. The focus is on the impact of public and private sector quality, generational change, and past purchase on demand. The results indicate that there has been generational change in buying behaviour, that the number of senior doctors employed in the public sector impacts upon demand for the private alternative, and that there is limited impact of habit in purchase. Changes to the structure of labour contracts in the NHS may affect demand for the private alternative.     

The wealth effects of premium subsidies on moral hazard in insurance markets

Insurance premium subsidies are present in many insurance markets. The Swiss government, for example, paid out CHF 4.26 billion or 0.72% of the Swiss GDP for health insurance premium subsidies in 2011. Analyses of premium subsidies have often highlighted that the increased insurance demand due to premium subsidies increases the effects of moral hazard in the market. Other consequences of premium subsidies, however, have mostly been neglected by the literature. We show in our theoretical model that the wealth effects of premium subsidies decrease the sensitivity of the insured towards the monetary consequences of losses. This leads to less prevention efforts by the insured and thus increases moral hazard in the market. The effect is preserved if the subsidy is financed through proportional taxation. Using two alternative models, we show that providing state-dependent subsidies can either increase or reverse this effect, depending on which state subsidies are paid. We argue that whether demand effects or wealth effects of premium subsidies will dominate the insured׳s behavior depends on the market structure.     

医疗保险支付方式的经济分析

本文在对医疗保险市场道德风险分析的基础上,运用经济学原理对医疗保险市场支付方式的作用机制进行了深入研究.结果表明,医疗保险支付方式不仅是一种医疗消耗的补偿手段,而且还是有效控制医疗费用,保障患者健康,正确引导供需双方行为,抑制道德风险的关键.因此,为了抑制供需双方的道德风险,控制医疗费用的不合理增长,医疗保险支付方式成为保险机构的首选工具.