International litigation and arbitration hinges on the use (and, sometimes, misuse) of “authorities” (i.e., precedents and the teaching and writings of “publicists”). Parties spend time and effort marshalling supportive authorities, distinguishing or refuting unhelpful ones, and monitoring legal developments in unrelated cases and in academic debates to bolster their legal arguments.

This practice has profound implications, for many key issues of international law (sources, role of precedent, etc.) are also questions about the nature, scope and relevance of authorities in international dispute settlement. There is however little research on the practice of citing authorities in international disputes, and even less empirical research that sheds light on such citations.

This thesis relies on data-led analyses that leverage the breadth of the collected dataset to identify noteworthy phenomena in the practice of citing in international legal disputes. On this basis, the thesis offers four novel contributions to international law scholarship.

First, it investigates whet determines the “authoritativeness” of authorities in international law, i.e., what makes them authoritative as opposed to merely persuasive. Relevant factors include an authority’s age, author, or main topic. Second, it identifies the differences in the citation practices of different protagonists in international disputes, and attaches these differences to distinct strategic motives. Third, the thesis concludes that the central role of authorities international legal debates means that authorities circumscribe what is international law and what is not; in other words, the “citable” tends to delimit the boundaries of what is considered international law.

The fourth and last contribution lies in the Dataset collected to conduct these analyses, which includes nearly 200,000 citations to precedents and scholarly teachings from more than 7,000 documents in cases before the ICJ, the ITLOS, WTO panels, investment arbitration tribunals and the IUSCT. This unprecedented Dataset, and the methods used to gather it, will hopefully serve as a basis or as a blueprint for future empirical research in international dispute settlement.