Dual market competition and deposit rate setting in Islamic and conventional banks

This paper addresses the issue of competition in dual banking markets by analyzing the determinants of deposit rates in Islamic and conventional banks. Using a sample of 20 countries with dual banking systems over the 2000–2014 period, our results show significant differences in the drivers of Islamic and conventional banks' pricing behavior. Conventional banks with stronger market power set lower deposit rates but market power is not significant for Islamic banks. In predominantly Muslim environments, conventional banks set higher deposit rates and further higher when their market power is lower. Whereas conventional banks are influenced by the competitiveness of Islamic banks, Islamic banks are only affected by their peers in predominantly Muslim countries. Our findings have important implications regarding competition and bank stability in dual banking markets.     

Does Islamic banking performance vary across regions? A new puzzle

This article investigates the performance of Islamic banks (IBs) across four different regions (Egypt, the Gulf, the UK and the US) in the aftermath of the subprime crisis. Using daily data and two performance ratio proxies (ROA (Return on Asset) and Tobin Q), we show that the performance of IBs varies significantly from one region to another, with the highest level for regions in the West. This result suggests a new puzzle as application of the same Sharia Board rules and sales of similar products should normally provide comparable performance outcomes for IBs.     

Extreme inequality aversion without separability

Hammond (J Econ Theory 11, 465–467, 1975), Meyer (J Econ Theory 11, 119–132, 1975), and Lambert (The distribution and redistribution of income Manchester University Press, Manchester, 2001) provide the formal result connecting leximin and the idea of extreme inequality aversion for social preferences of the expected utility type. Using an analogous approach, we show that for social preferences not necessarily satisfying the separability axiom that underlies expected utility theory, the case of extreme inequality aversion is covered by the class of weakly maximin social preferences—i.e., the class of social preferences that give priority to the worst off in all cases in which the worst off is not indifferent. I wish to thank Bart Capéau, Frank Cowell, Peter Lambert, Luc Lauwers, Erik Schokkaert, Frans Spinnewyn, and Bertil Tungodden for valuable comments. Remaining shortcomings are mine. Financial support from the Fund for Scientific Research - Flanders (grant G.0005.04) and the Interuniversity Attraction Poles network funded by the Federal Public Planning Service, Belgian Science Policy (grant P5/21-A) is gratefully acknowledged.     

Intertemporal substitution, risk aversion and ambiguity aversion

Summary. This paper axiomatizes a form of recursive utility on consumption processes that permits a role for ambiguity as well as risk. The model has two prominent special cases: (i) the recursive model of risk preference due to Kreps and Porteus [18]; and (ii) an intertemporal version of multiple-priors utility due to Epstein and Schneider [8]. The generalization presented here permits a three-way separation of intertemporal substitution, risk aversion and ambiguity aversion.Received: 5 August 2003, Revised: 12 March 2004, JEL Classification Numbers: D80, D81, D90.I am grateful to Larry Epstein for his guidance and invaluable advice, and to a referee for helpful comments and suggestions.     

Estimation of relative risk aversion across time

This article examines relative risk aversion in the framework of a three-moment asset pricing model that accounts for skewness. Accounting for skewness in calculating risk aversion gives a more accurate series of estimates of risk aversion and helps to reconcile the wide disparity in risk coefficients found in past literature. Risk aversion coefficients are calculated from 1926 to 2014 using stock market returns. This procedure results in a time series of data that can be related to other variables such as real interest rates and changes in demand for various asset classes.     

Regulating a risk-averse firm under incomplete information

We examine the optimal regulatory policy for a risk-averse firm when the firm is imperfectly informed about its efficiency parameter for a project at the time of contracting. The firm’s risk aversion shifts the optimal regulatory policy from a fixed-price contract to a cost-plus contract. The optimal regulatory policy entails undereffort by an inefficient firm as in Laffont and Tirole (J Polit Econ 94(3):614–641, 1986) and the effort distortion increases as the firm becomes more risk-averse. Further, the regulator benefits from sequential contracting with the firm where the firm chooses contract terms gradually as it acquires information, albeit the benefit diminishes as the firm becomes more risk-averse.      

Utility functions of equivalent form and the effect of parameter changes on optimum decision making

We derive a class of utility functions that are equivalent with respect to a well-defined functional form. We study the case of constant relative risk aversion (of some order) to investigate on different equivalence relations in order to determine the, possibly infinite, number of equivalence classes when utility functions satisfy a specific form. Then we apply our results to standard applications in economics and finance, for example, to the effect of price volatility on optimum hedging. We would like to thank Bernhard Eckwert and Itzhak Zilcha for constructive comments and suggestions.     

Forecasting risk attitudes: An experimental study using actual and forecast gamble choices

We develop and evaluate a simple gamble-choice task to measure attitudes toward risk, and apply this measure to examine differences in risk attitudes of male and female university students. In addition, we examine stereotyping by asking whether a person's sex is read as a signal of risk preference. Subjects choose which of five 50/50 gambles they wish to play. The gambles include one sure thing; the remaining four increase (linearly) in expected payoff and risk. Each subject also is asked to guess which of the five gambles each of the other subjects chose, and is paid for correct guesses. The experiment is conducted under three different frames: an abstract frame where the two highest-payoff gambles carry the possibility of losses, an abstract frame with no losses, and an investment frame that mirrors the payoff structure of the former. We find that women are significantly more risk averse than men in all three settings, and predictions of both women and men tend to confirm this difference. While average guesses reflect the average difference in choices, only 27 percent of guesses are accurate, which is slightly higher than chance.     

More on parametric characterizations of risk aversion and prudence

Summary. This note provides an alternative proof for the equivalence of decreasing absolute prudence (DAP) in the expected utility framework and in a two-parametric approach where utility is a function of the mean and the standard deviation. In addition, we elucidate that the equivalence of DAP and the concavity of utility as a function of mean and variance, which was shown to hold for normally distributed stochastics in Lajeri and Nielsen [4], cannot be generalized. Received: November 27, 2000; revised version: November 26, 2001 Correspondence to: T. Eichner     

Repetitive risk aversion

We propose a reasonable condition, which we call repetitive risk aversion (RRA), to be imposed on any utility function to account for the observed data on the relationship between the degree of absolute risk aversion and wealth. We deduce this condition from the concept of the fear of ruin (Aumann and Kurz 1977) and show it to be equivalent to the behaviorally meaningful condition that the risk premium is increasing at a non-increasing rate with the size of the bet. We drive mixed risk aversion, which is known to be stronger than standard and thus proper risk aversion, from RRA. We present several economic applications of RRA to demonstrate that it delivers better comparative static results.I am thankful to Jacques Drèze and Louis Eeckhoudt for their comments. I greatly appreciate the comments of an anonymous reviewer of this journal which have resulted in substantial improvement to both the content and presentation of the paper. An earlier version of this paper was presented at seminars at Brown, CORE, Hopkins, HKUST, Yale, and IMS     

Parametric characterizations of risk aversion and prudence

Summary. Our first main result says that whether one decision maker is more risk averse than another can be determined from their attitudes toward a given two-parameter family of risks. When all risks belong to this family, risk aversion can be compared even when initial wealth is random. Our second main result solves a long-standing problem in mean-variance analysis: what is the interpretation of the concavity of utility as a function of mean and variance? We show that in the case of normal distributions, this utility function is concave if and only if the agent has decreasing prudence. Received: July 29, 1996; revised: October 2, 1998