A New Test Toward Consistency in International Investment Arbitration.

This article addresses the challenge of inconsistency in international investment arbitration, where the absence of a unified adjudicatory hierarchy and the evolving nature of investment law hinder the strict application of doctrines like stare decisis or jurisprudence constante. It proposes a "soft precedents test" requiring tribunals to consider prior rulings in good faith when confronted with the same or similar issues, with the primary aim of fostering the development of international investment law while preserving necessary flexibility. The test confines the scope of precedents to those cited by the parties or identified by tribunals, and suggests linking compliance to existing annulment and enforcement mechanisms to incentivize adherence. This approach seeks to balance the need for consistency and coherence with the fragmented and dynamic character of investor-State dispute settlement, thereby enhancing the legitimacy and predictability of the investment arbitration regime.