Regret aversion: A new consideration for rational choice?

This talk examines patterns of preferences that may seem intuitive, and that characterise many real-world agents, but that deviate from orthodox normative decision theory. These preferences even deviate from less orthodox decision theories designed to accommodate risk aversion. Such preferences exhibit not risk aversion but regret aversion: a preference for one's chosen option to be more likely to actually turn out better (or perhaps far better) than the alternatives would Is regret aversion rational? Plausibly, yes. Beyond mere intuitions about cases, I provide two motivations for regret aversion being rational. The first is that it correctly diagnoses and treats what's wrong with the so-called 'fanatical' verdicts that orthodox decision theory gives us in cases of extremely low probabilities and extremely high stakes. The second motivation is that regret aversion is needed to reflect at least some concern for doing what is objectively best, and it is plausible that such a concern is rational, especially in moral decision-making. But there are also reasons to think regret aversion irrational: it leads to violations of several widely held and seemingly plausible principles of rationality.

Perhaps these violations constitute a decisive objection to regret aversion or, perhaps, regret aversion reveals that those principles must be false.

Hayden Wilkinson recently joined NTU as a Nanyang Assistant Professor in Philosophy. His research and teaching focuses primarily on ethics and rationality—on what decision-makers ought to do, both morally and rationally. He is particularly interested in how we should make decisions when we face circumstances with both extremely high stakes and extreme uncertainty as to how our actions will turn out, including in the many practical settings where these hold true. Before joining NTU, he was a Lecturer at the University of Western Australia and, before that, a Research Fellow in Philosophy at the University of Oxford's Global Priorities Institute. He completed his PhD in 2021 at the Australian National University, during which he held visiting fellowships at Oxford and at Princeton University, under a Fulbright Scholarship.