Information and capacities (Q1402923)

The paper deals with the phenomenon of the existence of negative information in non-Bayesian decision making. In the first part of the paper, the information value problem is reconsidered for Choquet expected utility maximizing approach. A necessary condition on the beliefs under which a positive information value is generated is derived. It is called Separative Monotonicity and its satisfaction by possibility and necessity rules is shown. Moreover, for certain conditioning rules, the information velue is always positive. In the second part of the paper, the criteria for the information value are questioned. It is suggested to reconsider the way in which the information is evaluated. A weaker requirement for the evaluation, called Statistical Dominance, is considered. Moreover, for a particular class of conditioning rules in the belief functions environment, rather strict necessary and sufficient conditions for positive information are analyzed.