Which courts matter most? Measuring importance in the eu preliminary reference system

In this article we contribute to a recent strand of literature that revisits the role of hierarchically different national courts in the process of European integration. While the received view emphasizes the dominance of lower courts in the preliminary reference procedure, more recent work documents the rise of peak courts as key interlocutors of the Court of Justice of the European Union (CJEU). Our contribution adds a hitherto underexplored variable to the existing research by focusing not only on how many references national courts send to Luxembourg but also what importance the CJEU attributes to each individual case. We find that peak court references are generally treated as more important than questions submitted by non-peak courts. Consequently, peak courts have bolstered their position vis-à-vis the CJEU in the process of legal integration. We base our findings on the most comprehensive preliminary rulings dataset to date (n = 10,609) that includes all cases received and decided by the Court between 1961 up to and including 2018.