The Circuit Splits Project (with Deborah Beim, University of Michigan) is the first comprehensive study of inter-circuit splits in the U.S. Courts of Appeals, within political science or legal scholarship. Circuits “split” when two or more circuits resolve the same legal question differently, causing similarly-situated litigants in different jurisdictions to be treated differently under the same exact federal law (whether statutory, constitutional, or precedential). Cases involved in splits are widely considered to be the core target cases for Supreme Court review. These cases provide an opportunity to study the relationship between the Supreme Court and circuit courts, the formation of the Supreme Court’s docket, significant changes to the path of law, and the role of ideology in shaping this path. They also allow us to study the strategies of interest groups pursuing policy agendas through litigation.
We collected an original dataset of circuit splits by organizing and supervising a team of Yale Law School research assistants, who read and coded over 21,000 opinions over the course of 2.5 years. The dataset includes both splits that have already been resolved by the Supreme Court and those that are ongoing. Uniquely, we capture every case in every circuit involved in each split.
Extant empirical work has examined only those splits that the Supreme Court chose to resolve, or only those cases with petitions explicitly alleging a circuit split. The former prevents inference about why the Court resolves some splits while letting others persist. The latter is blind to the context in which the Court considers the petition; for example, has the Court considered addressing this legal question before, why did it decline to do so, why might it decide to do so now? And yet these are exactly the sorts of questions the Justices themselves ask when deciding to whether to grant a particular petition.
Our data overcome these limitations by collecting all cases that implicate the precise legal matter over which there is the split. Thus, our theory and analysis can move beyond an account of which cases are decided to which legal issues the Supreme Court chooses to address, and when. That is, we advance the literature on certiorari by modelling what the Supreme Court actually considers when making its docket.
We are careful to recognize these and other strategic issues in our analysis. The payoff is that we have learned striking new patterns in this path of legal development, some of which challenge core stylized “facts” that have become the folk wisdom of circuit splits.
For example, in the first paper using these data, “Legal Uniformity in American Courts” (Journal of Empirical Legal Studies), we find that, contrary to conventional wisdom, most circuit splits are not resolved by the Supreme Court. As we hypothesize in our theorizing about the politics of such splits, active and important splits are more likely to be resolved—but many active and important splits persist indefinitely and continue to generate significant litigation. There is scholarly debate as to whether splits should be resolved immediately to clarify law or whether the Court can learn about the best doctrine by letting splits persist for some time. However, this debate is irrelevant in light of our findings. If never resolved, splits simply undermine the uniform interpretation of federal law, a value as old as Federalist 80.
In the second paper “Ideology, Certiorari, and the Development of Doctrine” (in progress), we turn to the partisan politics of circuit splits. We argue that splits present the Supreme Court with the opportunity to cheaply adopt one doctrine while obviating another. Thus, an ideologically-motivated Court should most want to review a polarized split, one with an ideologically allied side and an opposed side. A crucial and distinctive component of this theory is that the Supreme Court does not monitor individual lower court decisions but instead monitors the doctrine articulated therein, with the latter of far more relevance because of the many future decisions and latent decisions affected. Because we capture all cases implicating a given legal question, our dataset of splits allows us, for the first time, to characterize the ideological valence of doctrine itself. To test our theory, we develop a measure of split polarization and find support for our prediction that polarized splits are more likely to be resolved. The implications of this finding for the development of the law are profound. As the lower courts become increasingly political through new appointments, then so too will the Court’s docket, the Court’s decision making, and legal doctrine itself.
In a third paper (planned), we will examine how policy-motivated litigants manipulate the growth of splits to achieve their desired outcomes nationally. Understanding litigant strategy is important in its own right as it shapes the development of law. But without taking into account litigant motivations, one cannot fully understand circuit splits, which are created and spread as the result of strategic interactions between judges and litigants, and, therefore, hierarchical review more generally.
In a fourth paper (planned), we return to the role of ideology in the judicial hierarchy. How ideology shapes judicial decision-making is the founding question of judicial politics. A common finding is that the Supreme Court, acting in a monitoring role over the lower courts, is more likely to review decisions made by ideologically distant lower courts. Yet in this literature scholars have been unable to distinguish between the Court’s choice to review a particular decision in a particular case from its choice to resolve a particular legal question. Thus conclusions about the Court’s ideologically-motivated monitoring behavior may be confounded by the types of legal issues that arise in “enemy” lower courts. Our dataset of conflicts allows us to hold constant the legal question across many cases, while “varying” the ideology of the lower court issuing the decision. Further, we can hold fixed the answer to the legal question itself (i.e., the actual doctrine) across cases on the same side of a conflict and see, under these ceteris paribus conditions, whether known results about ideology still hold.