Fear of ruin and longevity enhancing investment

Rectangularization of the survival probability seems to be an ongoing process. It results from a higher concentration of the ages at death; but it can be reversed by a continuous increase in the limit of life time. In this paper, we assume that these two factors are endogenous and we show that risk averse decision makers exhibit a bias towards rectangularization. More specifically, the importance of the bias depends upon the intensity of the "fear of ruin" which is another measure of the degree of absolute risk aversion.longevity, fear of ruin

Putting Risk in its Proper Place

This paper examines preferences towards particular classes of lottery pairs. We show how concepts such as prudence and temperance can be fully characterized by a preference relation over these lotteries. If preferences are defined in an expected-utility framework with differentiable utility, the direction of preference for a particular class of lottery pairs is equivalent to signing the nth derivative of the utility function. What makes our characterization appealing is its simplicity, which seems particularly amenable to experimentation.properness, prudence, risk apportionment, risk aversion, stochastic dominance, temperance, utility premium

Changes in Risk and the Demand for Saving

How does risk affect saving? Empirical work typically examines the effects of detectible differences in risk within the data. How these differences affect saving in theoretical models depends on the metric one uses for risk. For labor-income risk, second-degree increases in risk require prudence to induce increased saving demand. However, prudence is not necessary for first-degree risk increases and not sufficient for higher-degree risk increases. For increases in interest rate risk, a precautionary effect and a substitution effect need to be compared. This paper provides necessary and sufficient conditions on preferences for an Nth-degree change in risk to increase saving.precautionary saving, prudence, stochastic dominance, temperance

How Diagnostic Tests Affect Prevention: a Cost-Benefit Analysis

The purpose of this paper is to offers insight for evaluating research and development in diagnostic tests. We show that a rational policy maker perfectly informed about health risks may choose to reduce investment in prevention when efficient diagnostic tests become available. We show that prevention and diagnostic tests are substitutes rather than complements. As a result the regular improvements in diagnostic technology that are observed can justify a lower investment on prevention at any given unitary price for this activity. The analysis is a useful tool for the allocation of funding between diagnostic and preventive medicine.prevention, diagnostic tests

Apportioning of Risks via Stochastic Dominance

Consider a simple two-state risk with equal probabilities for the two states. In particular, assume that the random wealth variable Xi dominates Yi via ith-order stochastic dominance for i = M,N. We show that the 50-50 lottery [XN + YM, YN + XM] dominates the lottery [XN + XM, YN + YM] via (N + M)th-order stochastic dominance. The basic idea is that a decision maker exhibiting (N + M)th-order stochastic dominance preference will allocate the state-contingent lotteries in such a way as not to group the two "bad" lotteries in the same state, where "bad" is defined via ith-order stochastic dominance. In this way, we can extend and generalize existing results about risk attitudes. This lottery preference includes behavior exhibiting higher order risk effects, such as precautionary effects and tempering effects.downside risk, precautionary effects, prudence, risk apportionment, risk aversion, stochastic dominance, temperance

Correlated risks, bivariate utility and optimal choices

In this paper, we consider a décision-maker facing a financial risk flanked by a background risk, possibly non-financial, such as health or environmental risk. A decision has to be made about the amount of an investment (in the financial dimension) resulting in a future benefit either in the same dimension (savings) or in the order dimension (environmental quality or health improvement). In the first case, we show that the optimal amount of savings decreases as the pair of risks increases in the bivariate increasing concave dominance rules of higher degrees which express the common preferences of all the decision-makers whose two-argument utility function possesses direct and cross derivatives fulfilling some specific requirements. Roughly speaking, the optimal amount of savings decreases as the two risks become "less positively correlated" or marginally improve in univariate stochastic dominance. In the second case, a similar conclusion on optimal investment is reached under alternative conditions on the derivatives of the utility function.bivariate higher order increasing concave stochastic dominance, precautionary savings, background risk, dependence

A benchmark value for relative prudence

In this paper we propose benchmark values for the coefficients of relative risk aversion and relative prudence on the basis of a binary choice model where the decision maker chooses between aggregating or disaggragating multiplicative risks. We relate our results to the decison maker's willingness to trade-off the second with the first and the third (central) moment of his wealthdistribution.relative risk aversion, relative prudence

A Good Sign for Multivariate Risk Taking

Decisions under risk are often multidimensional, where the preferences of the decision maker depend on several attributes. For example, an individual might be concerned about both her level of wealth and the condition of her health. Many times the signs of successive cross derivatives of a utility function play an important role in these models. However, there has not been a simple and intuitive interpretation for the meaning of such derivatives. The purpose of this paper is to give such an interpretation. In particular, we provide an equivalence between the signs of these cross derivatives and individual preference within a particular class of simple lotteries.correlation aversion, multivariate risk, prudence, risk aversion, temperance