Precedent, 'Jurisprudences Constantes' and Coherence in International Investment Arbitration : A Reappraisal of the Role of Earlier Decisions in the Practice of Arbitration Tribunals

Despite the non-binding nature of investment arbitration decisions beyond the circle of disputing-parties, arbitration tribunals rely on earlier decisions ‘whenever they can'. However, arbitration practice shows that opinions diverge when it comes to deciding how much influence those earlier arbitration decisions should exert. These diverging opinions result from disagreements over the nature of international investment law and arbitration, as well as from the implementation of different approaches and methodologies, especially positivistic and ‘policy-oriented' approaches.In this context, the objective of this article is twofold. First, it endeavors to map the various arguments put forth to support these diverging opinions as well as unearth the above-mentioned underlying conceptions and approaches. Then, this article jumps into the debate. It claims that, because of the evolution of international investment law, coherence is crucial for policy-makers, local populations and foreign investors. It consequently argues in favor of the development of jurisprudences constantes in international investment arbitration, embodied in series of consistent arbitration decisions