Jurisdictional Overlap in WTO Dispute Settlement and Investment Arbitration

The 'problem' of overlapping international disputes has long vexed scholars and adjudicators. This article addresses an increasingly important form of overlap that has begun to emerge: parallel or successive disputes before the World Trade Organization (WTO) and investor-state arbitral tribunals. This overlap does not give rise to judicial competition, and these proceedings are largely complementary. But they raise the possibility of conflicting factual and legal determinations, inconsistent remedies, and inefficiencies.This article considers various techniques for addressing this form of overlap, in light of existing jurisprudence, scholarly commentary, and treaty practice. We conclude that investment tribunals generally have greater flexibility in confronting situations of overlap than WTO panels and the Appellate Body. Nonetheless, many of the traditional adjudicative approaches to overlap, such as res judicata, have little bearing on the phenomenon of overlapping WTO and investment disputes. This article explores alternative approaches, grounded in considerations of comity and case management. We also consider treaty-based approaches, such as subject matter carve-outs and fork-in-the-road clauses. We conclude that 'softer' treaty provisions, which provide decision-makers with more authority and guidance in confronting situations of overlap, hold greater promise