Epistemic Foundations for Set-algebraic Representations of Knowledge

This paper formalizes an informal idea that an agent's knowledge is characterized by a collection of sets such as a -algebra within the framework of a state space model of knowledge. The formalization is based on the agent's logical and introspective abilities and on the underlying structure of the state space. The agent is logical and introspective about what she knows if and only if her knowledge is summarized by a collection of events with the property that, for any event, the collection has the maximal event included in the original event. When the underlying space is a measurable space, the collection becomes a -algebra if and only if the agent is additionally introspective about what she does not know. The paper characterizes why the agent's knowledge takes (or does not take) such a set algebra as a -algebra or a topology, depending on the agent's logical and introspective abilities and on the underlying environment.

Journal of Economic Literature Classification Numbers: C70, D83