Decision making with Expected Shortfall and spectral risk measures: The problem of comparative risk aversion

We analyze spectral risk measures with respect to comparative risk aversion following Arrow (1965) and Pratt (1964) for deterministic wealth, and Ross (1981) for stochastic wealth. We argue that the Arrow–Pratt-concept per se well matches with economic intuition in standard financial decision problems, such as willingness to pay for insurance and simple portfolio problems. Different from the literature, we find that the widely-applied spectral Arrow–Pratt-measure is not a consistent measure of Arrow–Pratt-risk aversion. Instead, the difference between the antiderivatives of the corresponding risk spectra is valid. Within the framework of Ross, we show that the popular subclasses of Expected Shortfall, and exponential and power spectral risk measures cannot be completely ordered with respect to Ross-risk aversion. Thus, for all these subclasses, the concept of Ross-risk aversion is not generally compatible with Arrow–Pratt-risk aversion, but induces counter-intuitive comparative statics of its own. Compatibility can be achieved if asset returns are jointly normally distributed. The general lesson is that these restrictions have to be considered before spectral risk measures can be applied for the purpose of optimal decision making and regulatory issues.     

Non-implementability of Arrow–Debreu equilibria by continuous trading under volatility uncertainty

In diffusion models, a few suitably chosen financial securities allow to complete the market. As a consequence, the efficient allocations of static Arrow–Debreu equilibria can be attained in Radner equilibria by dynamic trading. We show that this celebrated result generically fails if there is Knightian uncertainty about volatility. A Radner equilibrium with the same efficient allocation as in an Arrow–Debreu equilibrium exists if and only if the discounted net trades of the equilibrium allocation display no ambiguity in the mean. This property is violated generically in endowments, and thus Arrow–Debreu equilibrium allocations are generically unattainable by dynamically trading a few long-lived assets.     

Non-concavity problems in the dynamic macroeconomic models: A note

This note provides a method to convert the dynamic models in Cysne [Cysne, Rubens P., 2006. A note on the non-convexity problem in some shopping-time and human-capital models. Journal of Banking and Finance 30 (10), 2737–2745] and in Cysne [Cysne, Rubens P., 2008. A note on “inflation and welfare”. Journal of Banking and Finance 32 (9), 1984–1987] to concave optimization problems. We do this by introducing new control and state variables in the models. Cysne (2006, 2008) restrict attention to continuous time models and derive parametric conditions to use Arrow’s sufficiency theorem. When the sufficient conditions presented in Cysne (2006) are satisfied (but not under the sharper sufficient conditions presented in Cysne (2008)) we can rewrite these models as concave optimization problems even if time is discrete.     

Rating the raters: Are reputation concerns powerful enough to discipline rating agencies?

Credit rating agencies (CRAs) are accused of bearing a strong responsibility for contributing to the subprime crisis by having been deliberately too lax in the ratings of some structured products. In response to this accusation, CRAs argue that such an attitude would be too dangerous for them, since their reputation is at stake. The objective of this article is to examine the validity of this argument within a formal model: Are reputation concerns sufficient to discipline rating agencies?We show that the reputation argument only works when a sufficiency large fraction of the CRA income comes from other sources than rating complex products. By contrast when rating complex products becomes a major source of income for the CRA, we show that it is always too lax with a positive probability and inflates ratings with probability one when its reputation is good enough.We provide some empirical support for this prediction, by showing that ceteris paribus, the proportion of subprime residential mortgage-backed securities (RMBS) that were rated AAA by the three main CRAs indeed increased over the last eight years.We analyze the policy implications of our findings and advocate for a new business model of CRAs that we call the platform-pays model.     

A note on “Inflation and Welfare”

This note provides an analytical confirmation and a refinement of [Lucas Jr., R.E., 2000. Inflation and welfare. Econometrica 68 (62), 247–274 (March)] numerical findings regarding the characterization of optimality in the shopping-time model presented in that paper. The original numerical analysis concludes that a coefficient of risk aversion (σ) greater than 0.01 is sufficient for optimality. Here we use Arrow’s sufficiency theorem to confirm this result and, more importantly, to show without more calculations how changes in parameters can affect it.     

Insurance demand in the presence of loss-dependent background risk

We analyze insurance demand when insurable losses come with an uninsurable zero-mean background risk that increases in the loss size. If the individual is risk vulnerable, loss-dependent background risk triggers a precautionary insurance motive and increases optimal insurance demand. Prudence alone is sufficient for insurance demand to increase in two cases: the case of fair insurance and the case where the smallest possible loss exceeds a certain threshold value (referred to as the large loss case). We derive conditions under which insurance demand increases or decreases in initial wealth. In the large loss case, prudence determines whether changes in the background risk lead to more insurance demand. We generalize this result to arbitrary loss distributions and find conditions based on decreasing third-degree Ross risk aversion, Arrow–Pratt risk aversion, and Arrow–Pratt temperance.     

Equilibrium in risk-sharing games

The large majority of risk-sharing transactions involve few agents, each of whom can heavily influence the structure and the prices of securities. In this paper, we propose a game where agents’ strategic sets consist of all possible sharing securities and pricing kernels that are consistent with Arrow–Debreu sharing rules. First, it is shown that agents’ best response problems have unique solutions. The risk-sharing Nash equilibrium admits a finite-dimensional characterisation, and it is proved to exist for an arbitrary number of agents and to be unique in the two-agent game. In equilibrium, agents declare beliefs on future random outcomes different from their actual probability assessments, and the risk-sharing securities are endogenously bounded, implying (among other things) loss of efficiency. In addition, an analysis regarding extremely risk-tolerant agents indicates that they profit more from the Nash risk-sharing equilibrium than compared to the Arrow–Debreu one.     

An empirical study of the usefulness of human resources turnover costs in australian accounting firms

This paper reports the results of a laboratory experiment designed to evaluate the usefulness of applying Human Resources Accounting (HRA) to the problem of labour turnover management decision making in a sample of Australian accounting firms. Useful was defined as a reduction in uncertainty and an increase in relevance and sufficiency. Using a pretest-post-test research design, 57 volunteer accountants responsible for personnel decisions were individually administered (1) a two-part pilot tested case study with and without Human Resources Turnover Costs (HRTC); (2) a questionnaire which measured subjects' response to levels of uncertainty, relevance and sufficiency of the information. Three specific hypotheses tested warranted the conclusion that HRTC information significantly reduced accountants' levels of uncertainty and increased their levels of relevance and sufficiency.     

Relative Risk Aversion as an Arc Elasticity

Risk aversion is the central reason why individuals purchase insurance and undertake other forms of risk management. But deriving the Pratt–Arrow coefficient of relative risk aversion from a utility function requires familiarity with differential calculus—a level of mathematics beyond the prerequisites for most introductory risk management courses. Thus, students are not exposed to one of the most important and fundamental concepts in the field unless and until they take more advanced courses. The present article demonstrates that relative risk aversion can be obtained as an arc elasticity using only elementary mathematics. This approach highlights the relationship between risk aversion and the demand for insurance, and integrates concepts from the principles of economics course, helping to unify the business curriculum. Numerical examples are easily computed and graphed using electronic spreadsheets, providing students with a hands-on learning experience. For sufficiently small risks, the arc elasticity measure reduces to the Pratt–Arrow coefficient, providing a platform for discussing the difference between large-scale and small-scale risk aversion in upper-level courses.     

海南省被征地农民基本养老保险项目投资收益需求测算

目前,为保障被征地农民的利益,相关省市已陆续出台了被征地农民养老保险的相关政策。为了满足养老金的支付需求,必须对资金的投资收益需求进行测算。依据海南省颁布的《海南省被征地农民基本养老保险暂行办法》(下称《暂行办法》)的相关规定,本文对海南省被征地农民养老保险资金的投资收益率需求做了测算,并对性别比例、平均年龄、消费价格指数等因素进行了敏感性分析。     

A Complete Analysis of Full Pareto Efficiency in Financial Markets for Arbitrary Preferences

This paper provides a complete analysis of the necessary and sufficient conditions for financial markets to achieve fully Pareto-efficient allocation of aggregate wealth through trade in economies with arbitrary preferences. We show that full Pareto efficiency obtains only if the market structure of contingent claims spans the information partition of a minimal aggregate wealth statistic and a Halmos-Savage sufficient statistic for the beliefs of the traders. All the known allocation efficiency results in the literature due to Arrow, Hakansson, John, Ross, and others are unified by this result.     

Can Micro Health Insurance Reduce Poverty? Evidence From Bangladesh

This article examines the impact of micro health insurance on poverty reduction in rural areas of Bangladesh. The research is based on household‐level primary data collected from the operating areas of the Grameen Bank during 2006. A number of outcome measures are considered; these include household income, stability of household income via food sufficiency and ownership of nonland assets, and the probability of being above or below the poverty line. The results show that micro health insurance has a positive association with all of these indicators, and this is statistically significant and quantitatively important for food sufficiency.     

Comparative precautionary saving under higher-order risk and recursive utility

Measuring and comparing the precautionary saving motive rest almost exclusively on the expected utility framework, and only focus on income risk or coefficients of the Arrow–Pratt type. We generalize the standard approach by characterizing comparative precautionary saving under recursive utility for increases in income risk and increases in risk on the saving return, including higher-order risk effects. We express the comparisons in terms of precautionary premia. In addition, we define a new class of preference coefficients, and derive the associated conditions to predict a stronger precautionary motive. The coefficients provide a detailed picture of the preferences sustaining precautionary saving and could be useful in applications.     

Financial Markets for Unknown Risks if Beliefs Differ

We consider a general equilibrium model with individual and collective risks. The article builds on a contribution by Chichilnisky and Heal, who show that contingent Arrow–Debreu equilibria can also be supported in economies with Arrow securities and mutual insurance contracts. However, they show this to be true in general only if beliefs are identical, a very restrictive assumption in the context of unknown risks. Moreover, they claim complete insurance in equilibrium to be impossible if beliefs are different. We show that even with different beliefs, firstly, complete insurance is possible in each statistical state, and secondly, contingent equilibrium can still be supported in economies with insurance and securities.     

Multiple Losses, EX ANTE Moral Hazard, and the Implications for Umbrella Policies

Under certain cost conditions the optimal insurance policy offers full coverage above a deductible, as Arrow and others have shown. However, many insurance policies currently provide coverage against several losses although the possibilities for the insured to affect the loss probabilities by several prevention activities (multiple moral hazard) are substantially different. This article shows that optimal contracts under multiple moral hazard generally call for complex reimbursement schedules. It also examines the conditions under which different types of risks can optimally be covered by a single insurance policy and argues that the case for umbrella policies under multiple moral hazard is limited in practice.     

Bear beta

We test whether bear market risk, time variation in the probability of future bear market states, is priced. We construct an Arrow–Debreu security that pays off in bear market states (AD Bear) from traded Standard & Poor’s (S&P) 500 index options and use its returns to measure bear market risk. We find that bear beta (exposure to bear market risk) has a strong relation with expected stock returns that is robust, persistent, and remains strong among liquid and large stocks. Historical bear beta also predicts future bear market risk exposure. We conclude that bear market risk is priced in the cross section of stock returns.     

Citizens’ adaptive or avoiding behavioral response to an emergency message on their mobile phone

Abstract

Since November 2012, Dutch civil defense organizations employ NL-Alert, a cellular broadcast-based warning system to inform the public. Individuals receive a message on their mobile phone about the actual threat, as well as some advice how to deal with the situation at hand. This study reports on the behavioral effects of NL-Alert (n = 643). The current risk communication literature suggested underlying mechanisms as perceived threat, efficacy beliefs, social norms, information sufficiency, and perceived message quality. Results indicate that adaptive behavior and behavioral avoidance can be predicted by subsets of these determinants. Affective and social predictors appear to be more important in this context that socio-cognitive predictors. Implications for the use of cellular broadcast systems like NL-Alert as a warning tool in emergency situations are discussed.     

A Shortcut Way of Pricing Default Risk Through Zero-Utility Principle

Pricing the default risk is a hot challenge for every risk manager. The problem is tackled in the framework of the zero‐utility principle. According to Pratt (1964) , an approximation of the risk premium should be proportional to the Arrow–Pratt absolute risk aversion coefficient and the variance. Is that still true as a default risk is concerned? The answer appears to be negative, because the variance does not look to be an appropriate tool for asymmetrical risk. On the other hand, fear of ruin coefficient and probability of default are proved to be well‐tailored tools for a preliminary pricing. Bid and ask price approximations are both elicited and a necessary condition for risk exchange set out.     

Humanity in O. Henry' s Short Stories

O. Henry was called "the founder of American stories" . In his works, he shows us a vivid picture of American society. Thus paper will analyze some typical short stories of O. Henry and give a brief conclusion on humanityin his works.     

Closing the Loop: Review Process Factors Affecting Audit Staff Follow‐Through

The PCAOB recently expressed concern regarding the sufficiency and effectiveness of review and supervision of audit fieldwork. For the audit review process to succeed as a quality control mechanism, any issues or questions identified by a reviewer must be adequately resolved and documented in the workpapers. If audit review fails to correct for errors/biases in the work of reviewees, there can be serious detrimental effects on audit quality and, in turn, financial statement quality. Our study extends the literature by examining the phase of the review process in which reviewees respond to (or “close”) notes/comments provided by their reviewers. Utilizing an experiment, we find that certain contextual factors (review timeliness and review note frame) influence reviewee follow‐through during this critical phase. Specifically, we find that a delayed review elicits significantly lower effort levels than a timely review. Review note frame (i.e., how the reviewer phrases the rationale given for the underlying directive of a review note) significantly affects reviewee effort and performance when the review is timely. Through mediation analyses, we explore the mediating effect of effort on performance. In addition, we find that reviewer delay leads to greater over‐documentation.