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Homogeneity, selection, and the faithfulness condition


The faithfulness condition (FC) is a useful principle for inferring causal structure from statistical data. The usual motivation for the FC appeals to theorems showing that exceptions to it have probability zero, provided that some apparently reasonable assumptions obtain. However, some have objected that, the theorems notwithstanding, exceptions to the FC are probable in commonly occurring circumstances. I argue that exceptions to the FC are probable in the circumstances specified by this objection only given the presence of a condition that I label homogeneity, and furthermore that this condition typically does not obtain in the FC’s intended domain of application.

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I would like to thank Richard Scheines for helpful comments on an earlier draft and Clark Glymour for discussion. I would also like to thank audiences at the 2004 meeting of the British Society for the Philosophy of Science (especially Dan Hausman) and the 2004 Konstanz Summer School on Causality, Ignorance, and Uncertainty, and two anonymous referees.

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Correspondence to Daniel Steel.

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Steel, D. Homogeneity, selection, and the faithfulness condition. Minds & Machines 16, 303–317 (2006).

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  • Causal inference
  • Directed acyclic graphs
  • Faithfulness condition