Causal Decision Theory

Causal decision theory holds that a rational agent should choose the action that causally produces the best expected outcome, conditioning on the intervention rather than on the observation. It is the dominant response to Newcomb's Problem, where evidential correlations between choice and outcome are misleading because they do not reflect causal influence. The theory's core commitment is that rationality tracks causal structure, not merely statistical dependency — a commitment that makes it the natural decision framework for strategic interaction, where an opponent's beliefs depend on your action but not in a way that the action itself causes the opponent's move. Yet causal decision theory struggles when the boundary between cause and correlation is itself a property of the model, not the world, as in quantum entanglement or social network contagion.\n\n\n