  We propose a decision theoretic framework that allows a decision maker to
express its causal model of the world. We extend the model of Savage (1972) by
allowing the decision maker (DM) to choose policy interventions prior to
choosing acts over the nonintervened variables. We define what it means for the
DM's choices to express the DM's belief that the relation between some
variables is causal. We provide axioms characterizing when the DM's causal
model, as expressed through the DM's choices, is represented as a directed
acyclic graph. A final axiom characterizes when the DM's causal model has a
representation like the one in Pearl (1995). Consequently, under this
additional axiom one can apply Pearl's results to identify the DM's causal
model from the DM's probabilistic model.
