A Separation-of-Powers Approach to the Supreme Court’s Shrinking Caseload

Since the end of the 1980s the Supreme Court has cut its caseload nearly in half. While this decrease has not gone unnoticed, researchers have largely focused their explanations on institutional factors, such as changes in personnel, creation of the certiorari pool, or an increase in the amount of discretion justices have to set their agenda. Most existing work fails to consider how the preferences of members of Congress and the president also contribute to this staggering decrease. I provide the first systematic examination of how extrainstitutional influences affect the size of the Court’s caseload. I examine the 1951–2016 terms of the Court to reveal that a constraining political environment significantly reduces the number of cases the justices agree to hear each term. These results suggest that the justices consider the preferences of actors in the other branches of government much earlier than their decisions on the merits.