We investigate a normative theory of incomplete preferences in the context of preliminary screening procedures. We introduce a theory of ranking in the presence of objectively incomparable marginal contributions (apples and oranges). Our theory recommends benchmarking, a method under which an...

We present a model of information aggregation in which agents' information is represented through partitions over states of the world. We discuss three axioms, meet separability, upper unanimity, and non-imposition, and show that these three axioms characterize the class of oligarchic rules,...

We introduce an ordinal model of efficiency measurement. Our primitive is a notion of e ciency that is comparative, but not cardinal or absolute. In this framework, we postulate axioms that we believe an ordinal efficiency measure should satisfy. Primary among these are choice consistency and...