Rethinking Procedural Design in ISDS

This article examines the relationship between procedural design and accessibility in investor– state dispute settlement (ISDS). It argues that the increasing proceduralization of contemporary investment arbitration has generated growing disproportionality between adjudicatory architecture and the scale of many investment disputes. Multi-phase proceedings, extensive document production, expert-heavy evidentiary processes, and expanding procedural expectations have progressively transformed ISDS into an increasingly resource-intensive system. The article develops the concept of procedural proportionality as a structural principle of adjudicatory design. It argues that procedural rules do not merely organize arbitration, but shape the practical conditions under which access to adjudication becomes possible. From this perspective, developments such as the Prague Rules, expedited arbitration procedures, and tribunal-led case management reflect an emerging institutional recognition that procedural expansion carries systemic costs. The article concludes that the future evolution of ISDS may depend on the development of differentiated procedural frameworks capable of calibrating procedural intensity to the scale and complexity of disputes while preserving meaningful access to international adjudication.