Coordinating Adjudication Processes

International investment tribunals, like all other international courts and tribunals, are created equal. This chapter focuses on genuine decisional fragmentation and the coordination of proceedings within the investment treaty regime, i.e. between parallel and subsequent investment arbitrations rather than cross-regime coordination of, for example, investment arbitrations and World Trade Organization (WTO) dispute settlement. Decisional fragmentation refers to divergent rulings in cases that share the same factual matrix. Numerous authors posit that inconsistent decisions are a particular risk in investment arbitration given the lack of internal (e.g. stare decisis) as well as external control mechanisms to ensure uniform arbitral decisions. The chapter examines what coordination tasks arise in international investment law (IIL), what the stakeholder interests related to these coordination tasks are and how overlapping jurisdictions of investment tribunals can be managed institutionally and procedurally. The distinction between jurisdiction and admissibility is an important element of successfully coordinating parallel investment arbitrations. The major advantage of declaring claims inadmissible is that it allows tribunals to fulfil their jurisdictional mandate – which many investments tribunals are keen to do – while coordinating proceedings through the lever of admissibility. After describing the structural features of IIL, and in particular the absence of stare decisis, Section 2 examines three coordination tasks that arise in IIL: related proceedings, mass claims and derivative shareholder claims.