Ducking trouble: Congressionally induced selection bias in the Supreme Court's agenda

Existing studies of congressional influence on Supreme Court decision making have largely failed to recognize the fact that the Court has a discretionary docket. We model the effects of congressional preferences on the certiorari decision and find strong evidence that the Court's constitutional agenda is systematically influenced by Congress. The Court's docket is significantly less likely to contain cases wherein there are large congressionally induced deviations between what the Court would like to do, and what it can do in its final rulings. This selection bias in the Court's docket can lead to considerable uncertainty in estimating the effects of congressional constraint on the Court's final decisions, including a failure to properly reject the null hypothesis of no constraint.