Rationality on the Rise: Why Relative Risk Aversion Increases with Stake Size

How does risk tolerance vary with stake size? This important question cannot be adequately answered if framing effects, nonlinear probability weighting, and heterogeneity of preference types are neglected. We show that the increase in relative risk aversion over gains cannot be captured by the curvature of the utility function. It is driven predominantly by a change in probability weighting of a majority group of individuals who exhibit more rational probability weighting at high stakes. Contrary to gains, noncoherent change in relative risk aversion is observed for losses. These results not onlynchallenge expected utility theory, but also prospect theory

Uncertainty Aversion Vs. Competence: An Experimental Market Study

ambiguity, competence, double auction, experiments, markets, D81, C91,

Attitudes Toward Catastrophe

International audienceIn light of climate change and other global threats, policy commentators sometimes urge that society should be more concerned about catastrophes. This paper reflects on what society's attitude toward low-probability, high-impact events is, or should be. We first argue that catastrophe risk can be conceived of as a spread in the distribution of losses. Based on this conception, we review studies from decision sciences, psychology, and behavioral economics that explore people's attitudes toward various social risks. Contray to popular belief, we find more evidence against than in favor of catastrophe aversion-the preference for a mean-preserving contraction of the loss distribution-and discuss a number of possible behavioral explanations. Next, we turn to social choice theory and examine how various social welfare functions handle catastrophe risk. We explain why catastrophe aversion may be in conflict with equity concerns and other-regarding preferences. Finally, we discuss current approaches to evaluate and regulate catastrophe risk