This paper proposes a model of the decision-maker’s confidence in his probability judgements, in terms of an implausibility measure – a real-valued function on the set of probability functions. A decision rule is axiomatised according to which the decision-maker evaluates acts using sets of...

One apparent reason for deferring a decision – abstaining from choosing, leaving the decision open to be taken by someone else, one’s later self, or nature – is for lack of sufficient confidence in the relevant beliefs. This paper develops an axiomatic theory of decision in situations...

One apparent reason for deferring a decision – abstaining from choosing, leaving the decision open to be taken by someone else, one’s later self, or nature – is for lack of sufficient confidence in the relevant beliefs. This paper develops an axiomatic theory of decision in situations...

This paper develops a belief update rule under ambiguity, motivated by the maxim: in the face of new information, retain those conditional beliefs in which you are more confident, and relinquish only those in which you have less confidence. We provide a preference-based axiomatisation, drawing...