Towards semi-automating European legislative harmonisation analysis: A harmonised glossary for LLM-based legal concept detection

Achieving legislative harmonisation within the European Union (EU) is a multifaceted challenge, hampered by various political, economic, and legal complexities. This article addresses the significant issue of noncompliance by EU member states in transposing EU laws into national frameworks, underscored by numerous infringement procedures. This work introduces a novel methodological framework that combines semantic knowledge modelling and transformer-based language models to address discrepancies in legislative harmonisation. Central to the proposed methodology is the creation of a comprehensive glossary designed to establish correspondences between European legislative concepts and their national counterparts, thus facilitating greater accuracy in legal harmonisation. By deploying Large Language Models (LLMs) for semiautomating concept detection, complemented by legal harmonisation expert's oversight, this research provides an exhaustive, explainable assessment of legislative approximation within the EU. The findings enrich the academic debate on legal harmonisation offering actionable tools designed to decrease the frequency and gravity of infringement procedures, while promoting a more unified and efficient legal framework across the Union. The complete dataset and resources are available at the following link: GitHubrepository.