Uncertain indemnity and the demand for insurance

This paper considers the demand for insurance in a model with uncertain indemnity. Uncertain indemnity tends to increase the demand for insurance for precautionary reasons, but it also tends to decrease the demand due to the risk created by indemnity uncertainty. When the coefficient of relative prudence is not too large, uncertain indemnity reduces the demand for insurance and partial coverage is optimal even at actuarially fair premiums. In addition, insurance may be an inferior good or a normal good, depending on the behavior of absolute risk aversion and the magnitude of the coefficient of relative risk aversion.     

Mitigating disaster losses through insurance

Losses from natural disasters have increased in recent years due to growth of population in hazard-prone areas and inadequate enforcement of building codes. This article first examines why homeowners have not voluntarily adopted cost-effective protective measures and have limited interest in purchasing insurance. It then proposes a disaster-management program which utilizes insurance coupled with well-enforced building codes to reduce future damage. Banks and financial institutions play a key role in this program by requiring inspections of homes as a condition for a mortgage. New forms of reinsurance coverage against catastrophic losses from natural disasters are necessary to protect insurers against potential insolvency from the next mega-disaster.     

Risk aversion for losses and the Nash bargaining solution

Theory and Decision - We call a decision maker risk averse for losses if that decision maker is risk averse with respect to lotteries having alternatives below a given reference alternative in...     

The Citizenship of Excluded Groups: Challenging the Consumerist Agenda

The language of consumerism suggests that through involvement in consumer processes, consumers can influence policy formation and service provision. This paper examines, as illustrative cases in Australia, how two groups of consumers, people with a mental illness and older people, engage with these consumer processes. It finds they critically evaluate the opportunity offered by consumer processes for inclusion in policy and programmes. Both people with a mental illness and interviewed older people indicated how they acted as "agents involved in interpreting their needs", despite finding that in consumer processes their needs were predefined. Rather than allowing themselves to be constructed as passive objects, they positioned themselves as active citizens, having agency not as individual consumers but through drawing on networks. The responses of both groups go some distance toward dismantling power differences between professionals and "consumers", suggesting that social policy and programmes for both people with mental illness and older people can and sometimes do develop in a context of greater inclusivity.     

The impact of governmental assistance on insurance demand under ambiguity: a theoretical model and an experimental test

This article deals with the impact of governmental assistance on insurance demand under ambiguity, i.e., in situations where probabilities are uncertain. First, using a model of insurance demand under ambiguity, we derive theoretical predictions about the impact of several governmental assistance programmes on optimal insurance demand. For example, governmental assistance through a fixed public support scheme implies that partial insurance is always optimal under fair insurance with ambiguity. Second, we present the results of an experiment designed to test these predictions. We find support for several of our theoretical predictions. For example, the presence of governmental assistance through a fixed public support scheme decreases individuals’ willingness to pay to be fully insured. Finally, we compare these results with those obtained for a risk situation. We find that, regardless of the form of governmental assistance, participants in the ambiguity context are consistently willing to pay more to be fully insured than participants in the risk situation.     

Insurance decisions for low-probability losses

It is widely accepted that individuals tend to underinsure against low-probability, high-loss events relative to high-probability, low-loss events. This conventional wisdom is based largely on field studies, as there is very little experimental evidence. We reexamine this issue with an experiment that accounts for possible confounds in prior insurance experiments. Our results are counter to the prior experimental evidence, as we observe subjects buying more insurance for lower-probability events than for higher-probability events, given a constant expected loss and load factor. Insofar as underinsurance for catastrophic risk is observed in the field, our results suggest that this can be attributed to factors other than only the relative probability of the loss events.

Ambiguous life expectancy and the demand for annuities

In this paper, ambiguity aversion to uncertain survival probabilities is introduced in a static life-cycle model with a bequest motive to study the optimal demand for annuities. Provided that annuities’ return is sufficiently large, and notably when it is fair, positive annuitization is known to be the optimal strategy of ambiguity neutral individuals. Conversely, we show that the demand for annuities decreases with ambiguity aversion and that there exists a finite degree of aversion above which the demand is non-positive: the optimal strategy is then to either sell annuities short or to hold zero annuities if the former option is not available. To conclude, ambiguity aversion appears to be a relevant candidate for explaining the annuity puzzle.     

Experimental markets for insurance

This article extends the large amount of research on double-oral auction markets to hazards that produce only losses. We report results from a series of experiments in which subjects endowed with low-probability losses can pay a premium for insurance protection. Insurers specify the price at which they are willing to assume the risk of a loss. Insurance prices approach expected value for a large range of probabilities and loss amounts. Subjects seem to realize losses are statistically independent. Prices are not affected by ambiguity about the probability of loss.     

Competence effects for choices involving gains and losses

We investigate how choices for uncertain gain and loss prospects are affected by the decision maker’s perceived level of knowledge about the underlying domain of uncertainty. Specifically, we test whether Heath and Tversky’s (J Risk Uncertain 4:5–28, 1991) competence hypothesis extends from gains to losses. We predict that the commonly-observed preference for high knowledge over low knowledge prospects for gains reverses for losses. We employ an empirical setup in which participants make hypothetical choices between gain or loss prospects in which the outcome depends on whether a high or low knowledge event occurs. We infer decision weighting functions for high and low knowledge events from choices using a representative agent preference model. For gains, we replicate the results of Kilka and Weber (Manage Sci 47:1712–1726, 2001), finding that decision makers are more attracted to choices that they feel more knowledgeable about. However, for losses, we find limited support for our extension of the competence effect.     

试论墨家对矛盾律排中律表述问题

人们对墨家关于矛盾律排中律的表述持有不同的学术观点。而墨家的逻辑体系的确揭示了矛盾律排中律在人们的思维实践中相互依存的规律。并且墨家对矛盾律排中律的表述具有合理性、科学性。我国古代墨家的逻辑观点,虽经历时代的不断演进,仍对后世学习研究并完善我国的逻辑学理论产生深远影响。     

Stake effects on ambiguity attitudes for gains and losses

We test the effect of stake size on ambiguity attitudes. Compared to a baseline condition, we find subjects to be more ambiguity seeking for small-probability gains and large-probability losses under high stakes. They are also more ambiguity averse for large-probability gains and small-probability losses. We trace these effects back to stake effects on decisions under risk (known probabilities) and uncertainty (unknown probabilities). For risk, we replicate previous findings. For uncertainty, we find an increase in probabilistic insensitivity under high stakes that is driven by increased uncertainty aversion for large-probability gains and for small-probability losses.     

Reinsurance and the liability insurance crisis

Insurance-industry accounts of the liability insurance crisis of the mid-1980s often cite disruption of supply in reinsurance markets as an important contributing factor. Economic theories of the crisis have not explored this explanation for the severity of the crisis. This article investigates the extent to which events in reinsurance markets affected liability insurance market outcomes. It documents significant shocks to reinsurance supply in the early 1980s and finds evidence of subsequent disruptions to the price and availability of reinsurance. Regression analysis of liability insurance profitability over the time period supports the hypothesis that problems in reinsurance markets played an important role in the crisis.     

Loss volatility,bankruptcy, and the demand for reinsurance

Insurers in our model reinsure to lower the risk of bankruptcy. In the conceptual part of the study, we show that given bankruptcy cost, reinsurance may be demanded even if the insurer is risk-neutral. The model allows us to assess how the insurer's surplus, size, and volatility of losses affect the amount of reinsurance the insurer purchases. As predicted by our comparative statics analysis, we find empirically that property/casualty and medical malpractice insurers with higher prereinsurance loss volatility, lower surplus-to-premium ratios, and smaller sizes demand more reinsurance.     

A Diamond-Stiglitz approach to the demand for self-protection

The existing research concerning the relationship between risk aversion and prudence and the demand for self-protection assumes that the loss variable follows a Bernoulli distribution, and that changes in the level of self-protection are mean preserving. The analysis here replaces these two very strong conditions with ones which are more general. When doing this, the method of analysis is also significantly modified. This modification includes representing a change in the level of self-protection using the procedure developed by Diamond and Stiglitz (Journal of Economic Theory 8:337-360, 1974) for representing a change in risk. This alternate representation allows the existing findings to be generalized considerably, and also simplifies the analysis.     

Probability weighting for losses and for gains among smallholder farmers in Uganda

Theory and Decision - Probability weighting is a marked feature of decision-making under risk. For poor people in rural areas of developing countries, how probabilities are evaluated matters for...     

Optimal insurance without expected utility: The dual theory and the linearity of insurance contracts

Models of the insurance markets and institutions are routinely based on expected utility. Since EU is being challenged by an increasing number of decision models, we examine whether EU-based models are robust in their predictions. To do so, we rework some basic models of optimal insurance contracts and equilibrium using the “dual” theory to EU of Yaari. When there is a single, insurable source of risk, dual theory permits only corner solutions if the contract itself is linear. This contrasts sharply with EU. Nonlinearity, and thereby the possibility of interior solutions, is introduced in two ways. First, the contract itself is nonlinear, i.e., a deductible insurance policy. Or second, the decision maker is subject to some background risk such as uninsurable risky assets or default of the insurer. When decision problems are subject to nonlinearity, the predictions on optimal insurance are more similar to, though not identical with, those generated with EU.     

Decriminalization of marijuana and the demand for alcohol, marijuana and cocaine

This study examines whether the decriminalization of marijuana in eleven states has affected self-reported usage of drugs. Generally, decriminalization is not found to significantly impact drug use. An implication is that the demand for drugs is highly inelastic with respect to incremental changes in the legal sanctions for possession of small amounts of marijuana.