Highest courts make final decisions but lack the means to enforce them. Consequently, their external environment can change utility calculations behind judicial decision-making, as well as the subsequent policy implementation by governments. This raises the question: How do external actors impact judicial decision-making? I will investigate the impact external actors take on judicial decision-making at the German Federal Constitutional Court. External actors, which constitutes the sets of actors which are not formally involved in a legal question, differ in their scope of issues, goals and resources from other well studied actors, such as governments. This shapes their opportunities for influence-taking. In this article, I examine how judicial decision-making is impacted by external actors filing briefs with the court. I argue that external actors provide information and impact decision transparency. Decision transparency is a pivotal moderator of a given case and its outcome, especially in the study of the strategic interaction of courts and governments. In consequence, understanding the influence of external actors on constitutional court procedures has major implications for our understanding of how external actor shapes the interaction between the political and the judicial sphere. Further, I discuss motivations for external actors to file briefs at the Supreme Court of the United States and assess to what extend they are applicable to Kelsenian-type constitutional courts.
Presented at EPSA 2022.