Incidental Jurisdiction in Investment Treaty Arbitration and the Question of Party Consent

Arbitral tribunals in investment treaty arbitration have not contributed much to the theoretical development of the concept of incidental jurisdiction, even though they have occasionally exercised it in practice. One possible explanation for their apparent reluctance to make explicit and greater use of the concept of incidental jurisdiction is the tendency to adopt a strict approach to jurisdiction governed by party consent. In this essay, I argue that incidental jurisdiction is not in tension with the consensual foundations of international jurisdiction when it is viewed as one inherent power of international courts and tribunals. Key to this argument is that incidental determinations are not binding, and therefore do not need to fall within party-defined jurisdictional limits.