Moral Uncertainty, Proportionality and Bargaining

Besides disagreeing about how much one should donate to charity, moral theories also disagree about where one should donate. In many cases, one intuitively attractive option is to split your donations across all of the charities that are recommended by theories in which you have positive credence, with each charity’s share being proportional to your credence in the theories that recommend it. Despite the fact that something like this approach is already widely used by real-world philanthropists to distribute billions of dollars, it is not supported by any account of handling decisions under moral uncertainty that has been proposed thus far in the literature. This paper develops a new bargaining-based approach that honors the proportionality intuition. We also show how this approach has several advantages over the best alternative proposals.