The augmented arbitrator in International Commercial Arbitration 5.0: Is arbitral soft law evolving from lex mercatoria to lex algorithmica?

Abstract

This paper examines the evolution of arbitration within the context of the technological transformation driven by artificial intelligence (AI), advancing the concept of International Commercial Arbitration 5.0 as a new developmental stage of the arbitral system. Adopting a doctrinal and evolutionary approach, the paper analyses the transition from the traditional normative framework grounded in the lex mercatoria, subsequently articulated through arbitral soft law, towards an increasingly technologized arbitral ecosystem in which an emerging lex algorithmica—understood as an algorithmically mediated normative layer—begins to take shape. On this basis, the study proposes a model of multilevel governance of international arbitration structured around three interrelated normative layers—lex mercatoria, arbitral soft law, and lex algorithmica— thereby formulating the Theory of the Three Normative Layers of International Commercial Arbitration 5.0. Building upon the Principles for the Use of AI developed by various arbitral institutions (soft law), as well as the European regulatory frameworks on AI (hard law), it puts forward a proposal for the technological reconfiguration of AI in Arbitration 5.0. The paper concludes that AI does not replace the arbitrator, but rather transforms them into an “augmented arbitrator,” and raises the question of whether Arbitration 5.0 truly represents its final stage or merely the threshold of Arbitration 6.0—and of what is yet to come.