A growing number of decision theorists have, in recent years, defended the view that rationality is permissive under risk: Different rational agents may be more or less risk-averse or risk-inclined. This can result in them making different choices under risk even if they value outcomes in exactly the same way. One pressing question that arises once we grant such permissiveness is what attitude to risk we should implement when choosing on behalf of other people. Are we permitted to implement any of the rationally permissible risk attitudes, is there some specific risk attitude that is required when choosing for others, or are we required to defer to the risk attitudes of the people on whose behalf we are choosing? This article elaborates on this question, explains its wider practical and theoretical significance, provides an overview of existing answers, and explores how to go about providing a more systematic account of how to choose on behalf of others in risky contexts.
Introduction: Permissiveness of Rationality under RiskA growing number of decision theorists have, in recent years, defended the view that rationality is permissive under risk in the following sense. Consider a decision problem under risk: There is an agent who faces a choice between a number of different options. She values the different potential outcomes of her choice to different extents, but she does not know for sure what outcome each of the options available to her will bring about. She can, however, assign probabilities to how likely different outcomes are to come about as a consequence of the available options. Those who believe that rationality is permissive under risk grant that rational agents are free to make such risky choices in more or less riskaverse or risk-inclined ways. If rationality is permissive under risk, then the probabilities assigned to the potential outcomes, along with knowing the extent to which the agent values the outcomes do not fix how she should rationally choose.The following example illustrates this idea. Suppose you have to choose between two different medical treatments to undergo for a life-threatening condition. These treatments do not affect the quality of your life, and you moreover judge each of your remaining years