A New Approach to Modeling Decision-Making under Uncertainty and Defining Subjective Probabilities

This paper presents axiomatic models of decision making under uncertainty that avoid the use of a state space. The models are (a) general subjective expected utility theory with action-dependent subjective probabilities and effect-dependent utilities (the cases of effect-independent preferences and effect-independent valuations are obtained as special instances) and (b) a nonexpected utility theory involving well-defined families of action-dependent subjective probabilities on effects and utility representation that is not necessarily linear in these probabilities (a probabilistic sophistication version of this model, with action-dependent subjective probabilities is obtained as a special case)