Utilitarianism, Welfare, and Information

Utilitarianism is often criticized for making assumptions about welfare comparisons that are too strong to be plausible. Roughly speaking, it assumes that all goods can be precisely measured and compared. This criticism applies both to classical utilitarianism, and to Harsanyi’s more sophisticated version.

However, joint work with Kalle Mikkola and Teru Thomas provides a response. Our version of utilitarianism, a generalization of Harsanyi’s, has almost unlimited flexibility when it comes to welfare comparisons. It allows for all kinds of incomparabilities. The post connects this flexibility with uncertainty.


Crudely put, utilitarianism is the thesis that one world is better than another if it contains greater total welfare. This theory of distribution has been much criticised. But it received a major boost in Harsanyi’s 1955 utilitarian theorem.

Harsanyi’s theorem seems to mainly be about expected utility theory. But this makes it subject to versions of some of the traditional criticisms, particularly in the assumptions it makes about welfare comparisons. But joint work with Kalle Mikkola and Teru Thomas provides a reply.