Since the turn of the century, investment treaty arbitration (ITA) tribunals have begun citing past decisions with increasing frequency. They do so despite the absence of any formal doctrine of stare decisis and the presence of structural obstacles to the use of precedent in this context. Scholarship in this area has focused on explaining the rise of this de facto doctrine of precedent and evaluating the merits of the practice. Few have grappled with more practical questions about how precedent should operate in this unique sphere, but even a cursory examination of ITA decisions would reveal that some order and discipline are needed if the practice is to continue.
This Article is the first to offer a comprehensive framework to guide ITA tribunals in the practice of precedent. It does so from the dual standpoints of interpreting precedent (how much deference is owed) and authoring precedent (how broadly or narrowly to write). The framework is designed to help tribunals at each stage balance the three key values of predictability, accuracy, and legitimacy that any system of precedent is expected to serve. And it shows how that balancing should be conducted in light of the distinctive institutional features that make ITA different from common law systems. At a high level, the proposal is to replace the common law approach of stable, incremental decisionmaking with a model of robust and contentious dialogue. That means tribunals should view past decisions skeptically and, in writing their own decisions, seek not just to resolve the immediate dispute at hand but to advance the broader conversation of which each case forms one part.
