Axioms of Causal Relevance

This paper develops a set of graphoid-like axioms for causal relevance, that is, statements of the form: \Changing X will not aaect Y if we hold Z constant". Both a probabilistic and deterministic deenition of causal irrelevance are proposed. The probabilistic definition allows for only two axioms, unless stability is assumed. Under the stability assumption, probabilis-tic causal irrelevance is equivalent to path interception in cyclic graphs. The deterministic deenition allows for all of the axioms of path interception in cyclic graphs, with the exception of transitivity.