Shaping the Supreme Court's Federal Certiorari Docket*
Scott, Kevin M., Justice System Journal
The size of the Supreme Court's discretionary docket has varied considerably over the last fifty years, and that variation has received more attention in both scholarly and journalistic circles in light of declines over the past fifteen years. To understand the sources of such variation, one must account for external and internal influences on the docket. This study shows that the Supreme Court's docket is not influenced by the ideological distance between the Supreme Court and the lower courts, nor is it driven by the internal division within the lower courts. The chief justice, as first among equals, also appears unable to affect the size of the docket. The justices' preferences appear to play the pivotal role in determining the size of the Court's docket. These findings add to the perception that justices are free of institutional constraints when making their decisions.
The Supreme Court's docket-the number of cases it accepts for decision-has eceived considerable attention over the past several years because of its remarkable decline, leading some to characterize it as the Court's "incredible shrinking docket" (Mauro, 2003). Scholars (Cordray and Cordray, 2001; Hellman, 1996; O'Brien, 1997) and Supreme Court commentators (Lacovara, 2003; Lane, 2004; Mauro, 2003) have been unable to refrain from speculation as to the cause of the recent decline, but those concerned with this phenomenon rarely mention that there has been considerable historical fluctuation in the number of cases heard by the Supreme Court. Despite the concern about the size of the Court's docket, only a few serious attempts to determine what factors influence the size of the Court's docket have been made. In particular, although some of the justices and some commentators have alluded to possible external influences on the Court's docket, the notion that forces beyond the justices' control might shape the Court's docket is largely unstudied. This article seeks to remedy that deficit by building an integrated model of the determinants of the principal part of the Court's docket, those cases taken on certiorari from the U.S. Courts of Appeals. By understanding the forces that have shaped the docket over the past fifty years, scholars can better appreciate what possible fluctuations might arise in the future. More complete knowledge of the influence of external factors on the Court's docket may offer insight into how the Supreme Court relates to the lower courts and how those lower courts influence the terrain from which the Supreme Court must choose the cases it wishes to decide.
EXPLANATIONS FOR JUSTICES' DOCKETING DECISIONS
Scholars know far more about what determines the justices' decisions to review an individual case than about how those patterns aggregate to form the Court's docket. There appears to be considerable agreement as to what factors influence the justices' votes to grant or deny certiorari. These are the presence of the United States government as petitioner or amicus, other amicus briefs, lower-court conflict, ideological direction of the lower court's decision, and the justices' beliefs about the outcome of the merits decision (Benesh, Brenner, and Spaeth, 2002; Caldeira, Wright, and Zorn, 1999; Perry, 1991; Provine, 1980). However, there appears to be less evidence on how these factors combine to create the Court's docket. If, for example, the presence of amicus briefs increases the likelihood the Court will hear a case, it becomes difficult to explain the fact that as the number of amicus briefs has increased, the size of the Court's docket has decreased. More generally, scholars lack the ability to link the factors that determine the likelihood of the acceptance of an individual case with the factors that influence the overall size of the Court's docket.
By the same token, despite an understanding of the type of cases that constitute the Court's docket, scholars have struggled to translate that knowledge into explanations of the factors affecting the docket's size. …