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

Prediction: The long and the short of it – Antony Millner (University of California, Santa Barbara) and Daniel Heyen (ETH Zurich)

Commentators often lament forecasters’ inability to provide precise predictions of the long-run behaviour of complex economic and physical systems. Yet their concerns often conflate the presence of substantial long-run uncertainty with the need for long-run predictability; short-run predictions can partially substitute for long-run predictions if decision-makers can adjust their activities over time. …

Moral uncertainty and public justification – Jacob Barrett (Global Priorities Institute, University of Oxford) and Andreas T Schmidt (University of Groningen)

Moral uncertainty and disagreement pervade our lives. Yet we still need to make decisions and act, both in individual and political contexts. So, what should we do? The moral uncertainty approach provides a theory of what individuals morally ought to do when they are uncertain about morality…