Replication Data for: The “Odd Party Out” Theory of Certiorari.

We study how the ideological positions of petitioners, respondents, and appeals panels influence the Supreme Court’s decision to hear cases. We theorize that the Court is more likely to grant cert petitions when there is (1) ideological distance between the parties and (2) the appeals panel is aligned with the winning side. In these cases, the petitioning party is an “Odd Party Out,” which conveys information about the possibility of lower court bias. We test the theory using a new dataset of almost 18,000 cert petitions that includes advocate and judge ideology. We find that cert is more likely when the petitioner—regardless of ideology—is the Odd Party Out. This effect is driven by civil cases, but is similar for low- and high-salience cases. We argue that our results are consistent with justices being more willing to exercise oversight when a possibility of ideological bias in lower courts exists.