Expected Value Under Normative Uncertainty

Maximising expected value is the classic doctrine in choice theory under empirical uncertainty, and a prominent proposal in the emerging philosophical literature on normative uncertainty, i.e., uncertainty about values. But how should Expectationalism be stated in general, when we can face both uncertainties simultaneously, as is common in life? Surprisingly, different possibilities arise, ranging from Ex-Ante to Ex-Post Expectationalism, with several hybrid versions. Expectationalism thus faces the classic dilemma between ex-ante and ex-post approaches. Different expectational theories reach diverging evaluations, use different modes of reasoning, and take different attitudes to risk; but they converge undre an interesting (necessary and sufficient) condition. We relate choice under normative uncertainty to choice by Harsany's impartial observer' and Rawls's person behind the 'veil of ignorance', who are uncertain about their own identity and values; and we relate Expectationalism under normative uncertainty to Harsanyi's linear approach to aggregating values of different individuals or identities