Democracy and Fake Agreement

It is well known that there are many forms of democracy. It seems likely that none of them is perfect. But when voters are uncertain about the consequences of what they are voting for, democracy is even more puzzling.

One idea that seems plausible is that if every member of society prefers X to Y, then society should be seen as preferring X to Y. But when uncertainty is involved, even that is a bad idea. This post explains why, with a practical illustration involving Brexit and Trump.

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.


My account of utilitarianism, and therefore the alternatives to it, is all about uncertainty. For simplicity, it is mostly stated in terms of risk, but work in progress explains how to make sense of it for a much wider range of ways of representing uncertainty.

A curiously related project with Branden Fitelson examines a new way of thinking about the foundations of comparative likelihood. We argue that it supports Dempster-Shafer belief functions, of which probability functions are a special case.


Ethics involves complicated problems that overlap with formal epistemology, philosophy of probability, decision theory, and game theory. No one could deny the relevance of mathematics to those subjects, so it would be remarkable if mathematical methods were not central to the study of ethics.

My own work especially involves axiomatic methods. Ordinary language is not well suited to the precise statement of axioms, and it is almost impossible to work out the consequences of even small sets of simple axioms without some mathematics.