Who is the Dominant Lawmaker? Arbitrator’s Perception of Dispute Settlement Clauses as Substantive Rights in Investment Arbitration

Arbitrators in investment treaty arbitration have not been reluctant to express their views on the access to international arbitration, provided for in dispute settlement clauses in investment treaties, as forming a part of substantive investor protection. The present paper aims at answering the question of whether arbitrators' perception of the access to arbitration as a substantive right of investors amounts to law-making, effected by requalifying procedural rules as substantive ones, or alternatively, by breaking the separation line between substantive and procedural rules. The paper does so particularly in the context of the application of most-favoured-nation clauses to dispute settlement clauses, as its scenario-study. The paper argues that such arbitrators' views do not amount to actual law-making, that the qualification of dispute resolution clauses as a means of investor protection is motivated by the tribunals' goal of achieving a particular outcome, and it appears as a language game of similar qualifications. However, the mere fact that a blurred separation line between substantive and procedural rules would be acceptable for arbitrators, leads to the conclusion that investment treaty arbitration does appear as a fragmentised field of international law, and that in this broader context arbitrators do become dominant lawmakers