The unexpected value of the future
Hayden Wilkinson (Global Priorities Institute, University of Oxford)
GPI Working Paper No. 17-2022, forthcoming in Ergo
Various philosophers accept moral views that are impartial, additive, and risk-neutral with respect to betterness. But, if that risk neutrality is spelt out according to expected value theory alone, such views face a dire reductio ad absurdum. If the expected sum of value in humanity’s future is undefined—if, e.g., the probability distribution over possible values of the future resembles the Pasadena game, or a Cauchy distribution—then those views say that no real-world option is ever better than any other. And, as I argue, our evidence plausibly supports such a probability distribution. Indeed, it supports a probability distribution that cannot be evaluated even if we extend expected value theory according to one of several extensions proposed in the literature. Must we therefore reject all impartial, additive, risk-neutral moral theories? It turns out that we need not. I provide a potential solution: by adopting a strong enough extension of expected value theory, we can evaluate that problematic distribution and potentially salvage those moral views.