Séminaire général

Conférence du Professeur Paul Weirich, de l’Université du Missouri.

The principle of dominance compares options by comparing their outcomes in each state of a partition of states. Its application using a decision table orders the options’ possible outcomes according to an order of the states that produce them. Any comparative principle that uses a comparison of options’ ordered possible outcomes should be permutation invariant—a change in the order of an option’s possible outcomes should not change the options’ comparison because the order is arbitrary. Permutation invariance offers a handy test of comparative
principles. The principle of dominance, applied using a decision table that orders states, is permutation invariant and passes the test. However, some recently proposed comparative principles, advanced to argue against a standard generalization of expected-utility maximization for decision problems with imprecise probabilities or utilities, are permutation sensitive. This
failing undercuts their opposition to the generalization.

Key Words: comparison of options; expected utility; incomplete preference-rankings; ordered
partitions; partition invariance