Ben Millwood🔸 comments on Against Doing Things

[Ben Millwood🔸]

forgive the self-promotion but here’s a related Facebook post I made:

The law of conservation of expected evidence, E(E(X|Y)) = E(X), essentially states that you can’t “expect to change your mind”, in the sense that, if you already thought that your estimate of (say) some intervention’s cost-effectiveness would go up by an average of Z after reading this study, then your EV should already have been Z higher before you read it. You should be balanced (in EV terms) between the possible outcomes that would be positive surprises and negative surprises, otherwise you’re just not calculating your EVs correctly.

Anyway, let’s take X to be global future welfare, and Y to be the consequences of some action you take. E(E(X|Y)) = E(X) means that the average global well-being given the outcome of your action is exactly the same as the average global well-being without the outcome of your action. So why did you bother doing it?