Giving Every Case Its (Legal) Due - The Contribution of Citation Networks and Text Similarity Techniques to Legal Studies of European Union Law

In this article we propose a novel methodology, which uses text similarity techniques to infer precise citations from the judgments of the Court of Justice of the European Union (CJEU), including their content. We construct a complete network of citations to judgments on the level of singular text units or paragraphs. By contrast to previous literature, which takes into account only explicit citations of entire judgments, we also infer implicit citations, meaning the repetitions of legal arguments stemming from past judgments without explicit reference. On this basis we can differentiate between different categories and modes of citations. The latter is crucial for assessing the actual legal importance of judgments in the citation network. Our study is an important methodological step forward in integrating citation network analysis into legal studies, which significantly enhances our understanding of European Union law and the decision making of the CJEU.

[1]  Loïc Azoulai,et al.  The ‘Retained Powers’ Formula in the Case Law of the European Court of Justice: EU law as total law? , 2011 .

[2]  Advaith Siddharthan,et al.  Recognizing cited facts and principles in legal judgements , 2017, Artificial Intelligence and Law.

[3]  Ryan C. Black,et al.  The Citation and Depreciation of U.S. Supreme Court Precedent , 2013 .

[4]  Mattias Derlén,et al.  The Court of Justice and the Ankara Agreement: Exploring the Empirical Approach , 2012 .

[5]  Urska Sadl,et al.  Case – Case-Law – Law: Ruiz Zambrano as an Illustration of How the Court of Justice of the European Union Constructs Its Legal Arguments , 2013, European Constitutional Law Review.

[6]  Yannis Panagis,et al.  Selecting the cases that defined Europe: Complementary metrics for a network analysis , 2016, 2016 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM).

[7]  James H. Fowler,et al.  Abstract Available online at www.sciencedirect.com Social Networks 30 (2008) 16–30 The authority of Supreme Court precedent , 2022 .

[8]  Hamish Cunningham,et al.  GATE-a General Architecture for Text Engineering , 1996, COLING.

[9]  Gunnar Beck,et al.  The Legal Reasoning of the Court of Justice of the EU , 2013 .

[10]  Hinrich Schütze,et al.  Introduction to information retrieval , 2008 .

[11]  A. Tversky Features of Similarity , 1977 .

[12]  Yannis Panagis,et al.  The Force of EU Case Law: A Multi-dimensional Study of Case Citations , 2015, JURIX.

[13]  Aleksandar Trklja,et al.  A corpus investigation of formulaicity and hybridity in legal language a case of EU case law texts , 2017 .

[14]  James H. Fowler,et al.  Strategic Citations to Precedent on the U.S. Supreme Court , 2013, The Journal of Legal Studies.