Pitfalls of Empirical Studies that Attempt to Understand the Factors Affecting Appellate Decisionmaking

This Article surveys the state of empirical analysis of decisionmaking in the federal courts of appeals. We conclude that empirical studies predict very little, if anything, about the effects of extralegal factors on appellate decisionmaking. The hypothesis that judicial decisionmaking is influenced by the ideology of judges only implicates extralegal factors if and to the extent that any such ideological influence is extrinsic to law. However, as we note, empirical studies fail to discriminate between forms of moral/political reasoning intrinsic to law and those extrinsic to law — in part because the measure of "ideology" is very crude, and in part because the role of legal factors is not taken into account.