Newcomb's Problem and Prisoners' Dilemma

Abstract

The relationship between Newcomb's problem, which involves an apparent paradox of prediction, and Prisoners' Dilemma is explicated. After describing a resolution to Newcomb's problem, due to John A. Ferejohn, that renders the two contradictory principles of choice in Newcomb's problem (dominance and expected utility) consistent, I show Prisoners' Dilemma to be a “symmetricized” version of Newcomb's problem in its payoff structure. The assumption about predictability of choice made for one player in Newcomb's problem, when applied to both players in Prisoners' Dilemma–one considered as a leader and the other as a follower–offers a resolution to this dilemma that, while consistent with the resolution offered by metagame theory, rationalizes the existence of a metagame solution within a probabilistic, rational-choice framework. The relevance of the mutual-predictability assumption to the solution of arms races, and tragedy-of-commons situations generally, is discussed.