Can We Turn People into Pain Pumps? On the Rationality of Future Bias and Strong Risk Aversion

Abstract

Future-bias is the preference, all else being equal, for negatively valenced events to be located in the past rather than the future, and positively valenced ones to be located in the future rather than the past. Strong risk aversion is the preference to pay some cost to mitigate the badness of the worst outcome. People who are both strongly risk averse and future-biased can face a series of choices that will guarantee them more pain, for no compensating benefit: they will be pain pumped. Thus, combining these preferences is rationally impermissible. Dougherty (2011) argues that this gives us reason to think that future-bias is rationally impermissible. This argument, and a similar one presented by Greene and Sullivan (2015), relies on the idea that if several preferences are not rationally combinable, then in the absence of some explanation of why they are not combinable, we should conclude that (at least) one of them is rationally impermissible. We take up this question by, inter alia, reflecting on the empirical results of a study we ran that probes people’s risk averse and future-biased preferences. We argue that the data, in conjunction with other considerations, suggests that we should not infer from the irrationality of the combination of these preferences to the irrationality of one of the preferences singly. We also argue that given the descriptive data about these preferences, there is no reason to think that, if one of them is rationally impermissible, then it is future-bias. Finally, we reflect on the general issue of whether individual preferences are rationally evaluable.