Screening risk-averse agents under moral hazard: single-crossing and the CARA case

Principal-agent models of moral hazard have been developed under the assumption that the principal knows the agent's risk-aversion. This paper extends the moral hazard model to the case when the agent's risk-aversion is his private information, so that the model also exhibits adverse selection. We characterize the optimal menu of contracts; while its detailed properties depend on the setting, we show that some of them must hold for all environments. In particular, the power of incentives always decreases with risk-aversion. We also characterize the relationship between the outside option and the optimal contracts. We then apply our results to testing for asymmetric information in insurance markets.The authors thank P.A. Chiappori, D. de Mezza, R. Myerson, C. Prendergast, the late S. Rosen, D. Webb and an anonymous referee for helpful discussions or comments, as well as seminar participants in Berkeley, Chicago, Montré al, Northwestern, Rome, Stanford and Wisconsin. Bruno Jullien gratefully acknowledges financial support from the Fédération Francaise des Sociétés d'Assurance; Bernard Salanié thanks the University of Chicago for its hospitality.     

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.     

Insurance contracts with imprecise probabilities and adverse selection

Summary. This article deals with optimal insurance contracts in the framework of imprecise probabilities and adverse selection. Agents differ not only in the objective risk they face but also in the perception of risk. In monopoly, a range of configurations that VNM preferences preclude appears: a pooling contract may be optimal, incomplete coverage may be offered to high risks, low risks may be better covered.Received: 1 November 2001, Revised: 15 April 2003, JEL Classification Numbers: D81, D82, G22.Useful suggestions by Emmanuelle Auriol, Bernard Bensaïd, Michéle Cohen, Isaac Meilijson and the anonymous referee are acknowledged. Correspondence to: M. Jeleva     

Insurance,self-control,and contract flexibility

We study a competitive insurance market in which some consumers have too optimistic expectations regarding their future use of preventive measures. When contracts are long-term and inflexible, such naive consumers would increase the costs of insurance for low-risk consumers. The competitive insurance market therefore offers flexible contracts that allow for switching between different tariffs. Sophisticated consumers choose a partial insurance tariff and remain low-risks. Naive consumers choose the same tariff, but later switch to full insurance, and become high-risks. If there are sufficiently many naive consumers, they pay a transfer to sophisticated consumers (so that high-risks subsidize low-risks). In contrast, there are no such transfers when contracts are short-term. The model generates novel implications for the time frame of insurance contracts and insurance requirements.     

Insurance,self-protection,and the economics of terrorism

This paper investigates the rationale for public intervention in the terrorism insurance market. It argues that government subsidies for terror insurance have the effect of discouraging self-protection and limiting the negative externalities associated with self-protection. Cautious self-protective behavior by a target can hurt public goods like national prestige if it is seen as “giving in” to the terrorists, and may increase the loss probabilities faced by others by encouraging terrorists to substitute toward more vulnerable targets. We argue that these externalities in protection are essential for normative analysis of government intervention in insurance markets and may also explain why availability problems in this market have engendered much stronger government responses than similar problems in other catastrophe insurance markets.     

WTO Exceptions as Insurance

The paper formalizes the notion that GATT exceptions such as antidumping and escape clause actions can act as insurance for import competing sectors affected by adverse price shocks. The authors use a general‐equilibrium model with several import competing sectors and assume incomplete markets so that agents cannot contract insurance. It is shown that sector‐specific contingent protection measures are superior to uniform contingent tariffs as an insurance mechanism. A tax‐cum‐subsidy policy (i.e., taxing all sectors in order to subsidize the shocked sector) also improves welfare and is superior to contingent protection.     

保险发展、储蓄结构变化与经济增长

在一个世代交叠的内生经济增长框架内分析了财产险和人身险促进经济增长的机制.研究发现,保险中介在跨时平滑行为主体面临的生产率风险和疾病风险冲击的同时,减少了行为人的流动性资产持有,提高了行为人的非流动性资产投资.在行为人的储蓄由流动性资产和非流动性资产构成的情况下,保险发展产生储蓄结构效应,而储蓄结构效应导致的非流动性资产投资的相对增加促进了资本和知识的积累,进而形成内生经济增长.基于中国数据的实证检验支持了这一机制.     

Incomplete Insurance and Non-expected Utility

This paper shows that the estimation of non-expected utility (Kreps–Porteus preference) based on the representative agent model is less robust with respect to the departure from complete markets than is the expected utility for the following reasons. First, the precautionary saving caused by uninsured shocks may be evaluated incorrectly. Second, the portfolio held by individual household includes not only marketable assets, but also non-marketable assets (e.g. human capital) in the context of incomplete markets. Third, returns on marketable assets may not provide sufficient information for recovering relevant parameters. The estimated parameters available from the existing empirical research are consistent with the biasedness of parameters implied by this study.
JEL Classification: E44, G12.     

Private Information in Life Insurance,Annuity, and Health Insurance Markets

Economic theory predicts that private information on risks in insurance markets leads to adverse selection. To counterbalance private information, insurers collect and use information on applicants to assess their risk and to calculate premiums in an underwriting process. Using data from the English Longitudinal Study of Ageing (ELSA), this paper documents that differences in the information used in underwriting across life insurance, annuity, and health insurance markets attenuate private information to different extents. The results are in line with – and might help to reconcile – the mixed empirical evidence on adverse selection across these markets.     

Livestock as Insurance and Social Status: Evidence from Reindeer Herding in Norway

The theory of livestock as a buffer stock predicts that agropastoralists facing substantial risks will typically use liquid assets such as livestock for self-insurance to smooth consumption. This paper examines this hypothesis for reindeer herders in Norway where the herders, in contrast to pastoralists in, say, sub-Saharan Africa, face well-functioning credit markets. Using survey data including slaughter responses to a hypothetical meat price increase, we test whether keeping reindeer as insurance against risks affects the slaughter response. Furthermore, we examine whether status motives for keeping large herds affect the harvest response to a changing slaughter price. As a background to the empirical analysis, a stochastic bioeconomic model describing Saami reindeer herding is formulated.     

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     

企业的性质:要素使用权交易合约之履行过程

本文对企业的性质进行了分析 ,发现企业的性质在于 ,企业是市场中由要素所有者签订的一组不完备的要素使用权交易合约的履行过程。要素使用权交易合约的履行过程包括要素投入、要素使用权 (核心是剩余控制权 )的行使以及要素增值的分配 (核心是剩余索取权的行使 )以及企业组织资本与组织资产的创造和使用等 ,这一过程融交易功能与生产功能于一体。该组合约的关键内容就在于企业剩余索取权与剩余控制权的安排。作为要素使用权交易合约的履行过程 ,企业与市场是不能截然对立分离的 ,即要素市场、资产及服务市场等与要素使用权交易合约的签订与履行是互为基础 ,互相促进的。     

On the macroeconomic effects of establishing tradability in weak property rights

The New Economy is closely associated with computing & communications technology, notably the Internet. We discuss property rights to, and trade in, the difficult-to-define intangible assets increasingly dominating the New Economy, and the possibility of under-investment in these assets. For a realistic analysis we introduce a Schumpeterian market environment (the experimentally organized economy). Weak property rights prevail when the rights to access, use, andtrade in intangible assets cannot be fully exercised. The trade-off between the benefits of open access on the Internet, and the incentive effects of strengthened property rights, depend both on the particular strategy a firm employs to secure property rights, and the protection offered by law. Economic property rights can be strengthened if the originator can find innovative ways to charge for the intangible assets. The extreme complexity of the New Economy and the large number of possible innovative private contract arrangements make it more important to facilitate the use and enforcement of private individualized contracts to protect intellectual property than to rely only on standard patent and copyright law. Enabling law is one proposed solution. Current patent legislation in the US has led to costly litigation processes weakening the position of small firms and individuals in patent disputes. The property rights of such firms and individuals could be strengthened with insurance or arbitration procedures.JEL Classification: D21, D23, D52, D82, H54, K11, K22, K41, L11, L23, M13, O14, O33An earlier version of this paper was presented at the 9th Congress of the International Joseph A. Schumpeter Society (ISS), Gainesville, Florida, USA, March 28-30, 2002. The paper is part of the Nödfor project on Schumpeterian Creative Destruction, notably the exit and bankruptcy process, based at the Ratio Institute, Stockholm.     

Corporate insurance with optimal financial contracting

Summary. This paper attemps to rationalize the use of insurance covenants in financial contracts, and shows how external financing generates a demand for insurance by risk-neutral entrepreneurs. In our model, the entrepreneur needs external financing for a risky project that can be affected by an accident during its realization. Accident losses and final returns are private information to the firm, but they can be evaluated by two costly auditing technologies. We derive the optimal financial contract: it is a bundle of a standard debt contract and an insurance contract with franchise, trading off bankruptcy costs vs auditing costs. We then analyze how this optimal contract can be achieved by decentralized trading on competitive markets when insurance and credit activities are exogenously separated. With additive risks, the insurance contract involves full coverage above a straight deductible. We interpret this result by showing how our results imply induced risk aversion for risk-neutral firms. Received: December 14, 1998; revised version: August 11, 1999     

Pareto efficient insurance contracts when the insurer's cost function is discontinuous

Summary. We consider the problem of efficient insurance contracts when the cost structure includes a fixed cost per claim. We prove existence of efficient insurance contracts and that the indemnity function in such contracts is non-decreasing in the damage. We further show that either there is no insurance, or the indemnity is positive for all losses, or efficient insurance contracts have a unique jump. We study variants of the model and provide a generalization to the case of non expected utilities. Our results are then applied to Townsend's model of deterministic auditing. Received: November 8, 2000; revised version: March 12, 2002 RID="*" ID="*" We are grateful to F. Salanié for pointing out an error in the previous version of the paper and for suggesting Proposition 6 to us. Correspondence to: R.-A. Dana     

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.     

中国保险市场与金融发展互动关系的实证研究

本文通过基于向量误差修正VEC模型的因果关系检验和Granger因果关系检验,分析我国各类保险市场发展水平和金融发展之间的长期与短期关系.虽然用M2/GDP和金融相关率FIR作为金融发展衡量指标所得的结果有所差异,但就总体而言,保险市场的发展与金融发展存在脱节现象,伴随金融发展而引起保险服务需求的增加对保险市场发展的促进作用仍相对微弱.随着金融体系的不断完善,金融发展对保险业的促进作用将会逐步加强.     

信用风险、出口信用保险和出口贸易关系的研究

文章基于厂商理论对信用风险、出口信用保险与最优出口量之间的关系进行理论分析,论证了信用风险对出口贸易的负面效应,以及政府支持的出口信用保险对外贸出口的推动效应;并通过对中国的出口规模和进口国国家信用之间的关系进行实证检验,验证了信用风险的负面贸易效应,阐明了对于信用评级下调的发达市场以及绝对信用评级较低、人均收入较低的新兴市场,中国不仅需要而且必须加强发挥出口信用保险的功能。     

Incomplete Markets, Transitory Shocks, and Welfare

Although equilibrium allocations in models with incomplete markets are generally not Pareto-efficient, it is often argued that quantitative welfare losses from missing assets are small when time horizons are long and shocks are transitory. In this paper we use a computational analysis to show that even in the simplest infinite horizon model without aggregate uncertainty welfare losses can be substantial. Furthermore we show that in this model welfare losses from incomplete markets do not necessarily disappear when one considers calibrations of the model in which agents become very patient. We argue that when the economic model is calibrated to higher frequency data, the period persistence of negative income shocks must increase as well. In this case the welfare loss of incomplete markets remains constant even as agents' rate of time preference tends to one. Journal of Economic Literature Classification Numbers: D52, D58, D60.     

Insurance Taxation and Insurance Fraud

It is common practice in the United States to impose a sales tax on insurance premiums. Insurance benefits are not taxed, and it is typically argued that they should not be taxed because they compensate for a loss. In this paper I present a case where the taxation of insurance benefits is preferable to the taxation of premiums. When insurance fraud is present—in the form of ex post moral hazard—a tax on insurance premiums increases the number of fraudulent claims in the economy, whereas a tax on insurance benefits may reduce fraud. More importantly, however, policyholders are made better off with a benefit tax than with a premium tax.