Logical omniscience and rational choice
نویسنده
چکیده
It is well-known that usual doxastic models (epistemic logic, probability) suffer from strong idealizations. By extension, models of decision making that elaborate on these doxastic models (e.g., models of choice under set-theoretic uncertainty ([LR85], chap.13) and the expected utility model) inherit these idealizations. To improve doxastic models is therefore an important aspect of bounded rationality. The most uneliminable of these idealizations is probably logical omniscience : in doxastic models, beliefs are closed under the consequence relation of classical logic. Any agent so modelled is supposed to believe all the consequences of his or her beliefs. There has been extensive works to solve this problem in the framework of epistemic logic ([FHMV95]), which corresponds approximately to set-theoretic models in the rational choice literature1. Surprisingly, there have been few attempts to investigate the extension of the putative solutions to the probabilistic representation of beliefs (probabilistic case) and to models of decision making (decision-theoretic case)2. The aim of this paper is to fill this gap. The remainder of the paper proceeds as follows. In section 1, the problem of logical omniscience and its most popular solutions are briefly recalled. Then, it will be argued that, among these solutions, non-standard structures are the best basis for an extension to probabilistic and rational choice models. Section 2 is devoted to the probabilistic case, and section 3 to the decision-theoretic case. We conclude in section 4.
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تاریخ انتشار 2004