Economic theory reduces the concept of rationality to internal consistency. As far as beliefs are concerned, rationality is equated with having a prior belief over a quot;Grand State Spacequot;, describing all possible sources of uncertainties. We argue that this notion is too weak in some...

In light of the interest in axiomatic models of decision making in recent years, one is led to ask, in what ways do axiomatic derivations advance positive economics? If economists are interested in predicting how people behave, without a pretense to change individual decision making, how can...

A decision maker faces a decision problem, or a game against nature. For each probability distribution over the state of the world (nature's strategies), she has a weak order over her acts (pure strategies). We formulate conditions on these weak orders guaranteeing that they can be jointly...