On the biological foundation of risk preferences

• 成果类型: Article
• 署名作者: Robatto, Roberto; Szentes, Balazs
• 署名单位: University of Wisconsin System; University of Wisconsin Madison; University of London; London School Economics & Political Science
• 刊物名称: JOURNAL OF ECONOMIC THEORY
• ISSN/ISSBN: 0022-0531
• DOI: 10.1016/j.jet.2017.10.002
• 发表日期: 2017
• 页码: 410-422
• 关键词: Risk preferences; EVOLUTION; expected utility

摘要

This paper considers a continuous-time biological model in which the growth rate of a population is determined by the risk attitude of its individuals. We consider choices over lotteries which determine the number of offspring and involve both idiosyncratic and aggregate risks. We distinguish between two types of aggregate risk: environmental variations and natural disasters. Environmental variations influence the death and birth rates, while natural disasters result in instantaneous drops in population size. Our main result is a utility representation of the evolutionary optimal behaviour. The utility is additively separable in the two types of aggregate risk. The term involving environmental variations is a von Neumann-Morgenstern utility which induces the same attitude towards both idiosyncratic and aggregate risk. The term involving disasters cannot be interpreted as an expected utility maximization and induces less tolerance towards aggregate risk. (C) 2017 Elsevier Inc. All rights reserved.