Decoding Judicial Cross-Citations: How Do European Judges Engage with Foreign Case Law?

How do judges engage with foreign case law? While prior research has identified some instances of courts willing to cite foreign judgments, details about the mode of engagement and the motivation of such cross-citations have often been left unexplored. This Article fills these gaps. It presents the results of the coding of a sample of 456 judgments with cross-citations between the private law supreme courts of twenty-eight European countries. Twenty-five variables were coded for each citation: for example, the length of the discussion of foreign case law, whether the court was interested in the result or the reasoning of foreign judgments, and whether the citations occurred within the context of EU law, international law and/or specific areas of the law. This Article presents and contextualizes (i.e., to "decode") this quantitative information. Amongst others, we find that courts from common law countries more often cite older foreign case law and provide a greater depth of engagement with it than courts from civil law countries, that many of the courts are mainly interested in the result and not the reasoning of foreign judgments, that most cross-citations are driven by reasons of comparative law (and not, for example, EU law or international law), and that cross-citations due to EU law are particularly prevalent in IP law and conflict of laws. More generally, we observe a form of bifurcation of citations across many of the topics analyzed, suggesting a divide, not between common and civil law countries, but between courts from smaller and larger jurisdictions (e.g., with smaller jurisdictions using citations in more traditional areas of law, citing mainly one other court, citing older cases, and more often being interested in the reasoning of foreign judgments).