Population ethical intuitions

Lucius Caviola (Harvard University), David Althaus (Center on Long-Term Risk), Andreas Mogensen (Global Priorities Institute, University of Oxford) and Geoffrey Goodwin (University of Pennsylvania)

GPI Working Paper No. 3-2024, published in Cognition

Is humanity's existence worthwhile? If so, where should the human species be headed in the future? In part, the answers to these questions require us to morally evaluate the (potential) human population in terms of its size and aggregate welfare. This assessment lies at the heart of population ethics. Our investigation across nine experiments (N = 5776) aimed to answer three questions about how people aggregate welfare across individuals: (1) Do they weigh happiness and suffering symmetrically?; (2) Do they focus more on the average or total welfare of a given population?; and (3) Do they account only for currently existing lives, or also lives that could yet exist? We found that, first, participants believed that more happy than unhappy people were needed in order for the whole population to be net positive (Studies 1a-c). Second, participants had a preference both for populations with greater total welfare and populations with greater average welfare (Study 3a-d). Their focus on average welfare even led them (remarkably) to judge it preferable to add new suffering people to an already miserable world, as long as this increased average welfare. But, when prompted to reflect, participants' preference for the population with the better total welfare became stronger. Third, participants did not consider the creation of new people as morally neutral. Instead, they viewed it as good to create new happy people and as bad to create new unhappy people (Studies 2a-b). Our findings have implications for moral psychology, philosophy and global priority setting.

Other working papers

Exceeding expectations: stochastic dominance as a general decision theory – Christian Tarsney (Global Priorities Institute, Oxford University)

The principle that rational agents should maximize expected utility or choiceworthiness is intuitively plausible in many ordinary cases of decision-making under uncertainty. But it is less plausible in cases of extreme, low-probability risk (like Pascal’s Mugging), and intolerably paradoxical in cases like the St. Petersburg and Pasadena games. In this paper I show that, under certain conditions, stochastic dominance reasoning can capture most of the plausible implications of expectational reasoning while avoiding most of its pitfalls…

The evidentialist’s wager – William MacAskill, Aron Vallinder (Global Priorities Institute, Oxford University) Caspar Österheld (Duke University), Carl Shulman (Future of Humanity Institute, Oxford University), Johannes Treutlein (TU Berlin)

Suppose that an altruistic and morally motivated agent who is uncertain between evidential decision theory (EDT) and causal decision theory (CDT) finds herself in a situation in which the two theories give conflicting verdicts. We argue that even if she has significantly higher credence in CDT, she should nevertheless act …

Longtermism in an Infinite World – Christian J. Tarsney (Population Wellbeing Initiative, University of Texas at Austin) and Hayden Wilkinson (Global Priorities Institute, University of Oxford)

The case for longtermism depends on the vast potential scale of the future. But that same vastness also threatens to undermine the case for longtermism: If the future contains infinite value, then many theories of value that support longtermism (e.g., risk-neutral total utilitarianism) seem to imply that no available action is better than any other. And some strategies for avoiding this conclusion (e.g., exponential time discounting) yield views that…