A Logic of Questions for Rational Choice

Abstract

When making a choice between competing alternatives, we are primarily guided by our preferences. But the process is typically aided by asking questions. The questions serve to expand the set of possibilities we consider. Nonetheless a reasonable condition we might impose on this process is that the order in which questions are asked is ultimately irrelevant. Someone for whom this is not the case can be manipulated into making unfortunate choices by a careful choice of questions. We develop a logic for reasoning about such processes, use this to provide an independent justification for the rationality of having transitive preferences, and explain what goes wrong in situations where preferences are not transitive, such as Condorcet’s voting paradox.