Are more risk averse agents more optimistic? Insights from a rational expectations model

We analyse a model of partially revealing, rational expectations equilibrium with diverse information, endogenous beliefs formation and uncertain distribution of risk aversion. More risk averse agents are then more optimistic. Such a positive correlation is important for collective decision analysis.     

Are risk‐averse agents more optimistic? A Bayesian estimation approach

Our aim is to analyze the link between optimism and risk aversion in a subjective expected utility setting and to estimate the average level of optimism when weighted by risk tolerance. Its estimation leads to a non‐trivial statistical problem. We start from a large lottery survey (1536 individuals). We assume that individuals have true unobservable characteristics. We adopt a Bayesian approach and use a hybrid MCMC approximation method to numerically estimate the distributions of the unobservable characteristics. We find that individuals are on average pessimistic and that pessimism and risk tolerance are positively correlated. Copyright © 2008 John Wiley & Sons, Ltd.     

Aggregation of heterogeneous beliefs

This paper is a generalization of [Calvet, L., Grandmont, J.-M., Lemaire, I., 2002. Aggregation of heterogenous beliefs and asset pricing in complete financial markets. Working paper] to a dynamic setting. We propose a method to aggregate heterogeneous individual probability beliefs, in dynamic and complete asset markets, into a single consensus probability belief. This consensus probability belief, if commonly shared by all investors, generates the same equilibrium prices as well as the same individual marginal valuation as in the original heterogeneous probability beliefs setting. As in [Calvet, L., Grandmont, J.-M., Lemaire, I., 2002. Aggregation of heterogenous beliefs and asset pricing in complete financial markets. Working paper], the construction stands on a fictitious adjustment of the market portfolio. The adjustment process reflects the aggregation bias due to the diversity of beliefs. In this setting, the construction of a representative agent is shown to be also valid.     

Convergence of utility functions and convergence of optimal strategies

In this paper we study the stability (in the L ^p as well as for the almost sure convergence sense) of the optimal investment-consumption strategy with respect to the choice of the utility function.Received: February 2003, The authors want to thank an anonymous referee as well as an associate editor for their useful comments and suggestions (in particular, the development on the speed of convergence). The authors also thank R. A. Dana for helpful discussions and W. Schachermayer for careful reading.     

National burden of road traffic injuries in Argentina

More than 1.2 million people die and as many as 50 million people are injured or disabled due to road traffic injuries (RTIs) every year worldwide. The lack of reliable data hinders efforts to describe the characteristics of the issue and prioritise prevention activities. The objective was to provide a snapshot of fatal and non-fatal RTI in Argentina. We used the methodology proposed by the Global Burden of Disease Injury Expert group. External causes of deaths with unknown codes were proportionately redistributed over the known categories. In 2007 in Argentina, we estimated 5915 RTI deaths, compared with 3983 RTI deaths reported previously by the Ministry of Health, accounting for 1931 additional cases. The highest number of deaths occurred in young men (15-29 years old), although the highest RTI death rates were in the age group of 55 years and older. Four-wheeled vehicle occupants were the most common road user type killed (59.1%); vulnerable road users represented one third (29.5%) of deaths and 64% of non-fatal RTI. The national and regional estimates of RTI in Argentina should help policy makers and public-health researchers to understand the importance of RTI prevention and design specific interventions to further reduce these preventable deaths and injuries.     

Destructive Entrepreneurship: The Cost of the Mafia for the Legal Economy

This article focuses on the infiltration of legitimate businesses by the mafia and on the existence of “legal mafia-owned enterprises” (i.e., legal, declared enterprises owned — directly or indirectly — by mafiosi). Crime economics often limits itself to the destructive aspects stemming from merely illegal activities. Mafia investments in the legal economy and mafia entrepreneurship are also an underestimated source of latent conflict that is costly to the economy and society. This article shows that mafia-owned legal enterprises establish a lasting, unproductive, and even destructive entrepreneurship. The mafia strives to create an artificial scarcity that affects only its non-members, and thus the mafia manages to dominate markets and other entrepreneurs. The mafia then turns from its initial appropriative functions into a rule-producing function in order to shape markets. More specifically, the mafia asserts itself as a competing sovereign thanks to its power to withhold resources obtained through property over productive entities.     

Conditional comonotonicity

Abstract In this paper we propose a generalization of the notion of comonotonicity by introducing and exploring the concept of conditional comonotonicity. We characterize this notion and we show by examples that conditional comonotonicity is the natural extension of the concept of comonotonicity to dynamic settings. Mathematics Subject Classification (2000): 90A05, 60Gxx Journal of Economic Literature Classification: D910, C610, G120