Decision Under Normative Uncertainty

How should we evaluate options when we are uncertain about the correct standard of evaluation, for instance due to conflicting normative intuitions? Such ‘normative' uncertainty differs from ordinary ‘empirical' uncertainty about an unknown state, and raises new challenges for decision theory and ethics. The most widely discussed proposal is to form the expected value of options, relative to correctness probabilities of competing valuations. We show that the expected-value theory is just one of four natural expectation-based theories. These theories differ in the attitudes to normative risk and to empirical risk. The ordinary expected-value theory imposes neutrality to normative risk, whereas its attitude to empirical risk is impartial, i.e., determined by the risk attitudes of the competing valuations deemed possible. The three other theories are, respectively, neutral to both types of risk; impartial to both types of risk; or neutral to empirical but impartial to normative risk. We conditionally defend the theory which is impartial to all risk - the impartial value theory - on the grounds that it respects risk-attitudinal beliefs rather than imposing an ad-hoc-risk attitude. Meanwhile, our analysis shows how one can address empirical and normative uncertainty within a unified formal framework, and rigorously define risk attitudes of theories.