Case complexity and the study of strategic behaviour at highest courts. The choice and implications of different measurement strategies to quantify case complexity.

Presented at: 13th Annual Conference of the European Political Science Association (EPSA), Glasgow, June 2023.

Case complexity is a key predictor in many studies of judicial politics. Specifically, case complexity is used to explain judicial behaviour towards politics and society. However, the definition and operationalization of case complexity are underdeveloped. Scholars propose different ways to specify case complexity based on linguistic features, types of decisions or issue areas. Yet, we know very little about the assumptions guiding different operationalizations and their substantive implications. This article presents a discussion of different concepts of case complexity to explain how case complexity influences the strategic interaction of highest courts and public actors. First, the article presents how different measures of case complexity are supported theoretically by legal and political research. Second, the different measurements are assessed empirically for the German Federal Constitutional Court, a prominent and influential domestic highest court. To understand how different operationalization affect the study of judicial behaviour, the impact of briefs on transparency-inducing action by judges is analyzed. The results have major implications for studies on judicial behaviour at highest courts.