ISDS 2.0: time for a doctrine of precedent?

The reform process for ISDS at UNCITRAL is reaching its climax. Within the next few years, a treaty for ‘ISDS 2.0’ should emerge from this process. A key feature of ISDS 2.0 will be a new international court for resolving investor–state disputes. This court should include an appellate tribunal. A core function of this appellate tribunal will be to produce consistent case law, noting a common complaint about ‘ISDS 1.0’ is that it has produced inconsistent case law. There is good reason to believe that the appellate tribunal of ISDS 2.0 can deliver consistent case law, but the promoters behind ISDS 2.0 need to be careful what they wish for. The WTO dispute settlement system produced consistent case law, yet that achievement turned out to be a reason for its subsequent breakdown. Consistent case law apparently sounds good in theory, but it is not welcome in practice. Is there a way out of this conundrum? This article proposes that a formal doctrine of precedent is the solution. This proposal might initially provoke some surprise—a softer system of precedent is apparently the best compromise. But a doctrine of precedent can be crafted to limit adjudicative law-making power, while emphasizing states’ control over their investment–treaty obligations. This article puts forward the broad outline of this conception of a doctrine of precedent, explains why it gives effect to states’ interests, and examines the methods by which a doctrine of precedent could be adopted.