Lucky you: Your case is heard by a seasoned panel—Panel effects in the German Constitutional Court

Panel effects have been widely studied in randomly composed panels. However, for many courts, panel composition stays constant. Then judges become familiar with each other. They know what to expect from each other. Mutual trust may develop. A local culture may emerge. If rejection is the default, familiarity is likely to help plaintiffs, as familiar panels can be more effective, and more self-confident. In the German Constitutional Court, the effect of familiarity on three success measures can be causally identified: success on the merits, with the request for a preliminary ruling, or with a procedural request. Justices experience multiple, exogenous recompositions of their chamber. In the logic of regression discontinuity, the effect of familiarity on the alternative measures for success can be identified if these recompositions lead to a clear decrease in familiarity with the other members of the chamber.