The Chances of Choices

Abstract

It is sometimes thought that if we treat decision-theoretic options as interventions, then we can use evidential decision theory to vindicate causal dominance reasoning. This is supposed to be guaranteed by a causal modeling axiom that implies that interventions are probabilistically independent of their non-effects—namely, the Causal Markov Condition. But there are two concerns for this line of reasoning. First, the Causal Markov Condition doesn’t imply that an agent should regard their intervention as probabilistically independent from its non-effects when the agent has “exotic evidence”—i.e., evidence about some variable that they regard as causally downstream from their intervention. Second, the Causal Markov Condition is not plausible when we interpret it as implying constraints on subjective probability distributions, because there are cases where it is rational for an agent to regard variables as causally independent but subjectively proba-bilistically dependent. In this paper, I argue that interventionists can answer these challenges by adopting a conception of choice according to which there are significant constraints on the objective probabilities for decision-theoretic options.