An Essay on Decision Theory with Imperfect Recall

In this paper, I seek to establish a framework in which solutions to imperfect recall decision problems can be suitably examined. I introduce a strategy concept which is an extension of the standard concept employed since von Neumann and Morgenstern, and show how it may provide optimal solutions to problems which feature forgetting. For a technical analysis, I provide a characterization of imperfect recall extensive forms, a crucial input into future studies on the properties of optimal extended strategies. Also, I discuss further issues in decision theory with imperfect recall, including the prospects of induced forgetting when preferences change during the problem.