On The Contribution of Investment Arbitration to Issues of Evidence and Procedure Before Other International Courts and Tribunals

This chapter examines the contribution of investment arbitration to international law more generally in relation to matters of evidence and procedure. Part 1 examines the practice of a number of inter-State dispute settlement fora in an attempt to gauge the contribution of the considerable body of practice of investment arbitration which has been built up over the course of the last few decades. It is shown that, at least at this point in time, this contribution is difficult to discern and appears to vary from one context to another. Part 2 takes a step back and considers the broader implications of the current practice and potential future developments. The argument is made that investment arbitration is in practice an important point of reference for the resolution of ‘cross-cutting’ issues of evidence and procedure, with significant potential to influence the handling of similar issues before other courts and tribunals. For instance, certain issues such as the challenge and disqualification of decision-makers, abuse of process, or admissibility of illegally-obtained evidence have received extensive consideration in investment arbitration. The manner in which such issues have been dealt with by investment arbitrators, it is argued, forms part of an increasingly rich corpus of practice from which other courts and tribunals can potentially draw inspiration. Accordingly, the strict position taken by some inter-State tribunals to date, which circumscribes reference to investment arbitration practice on account of it not being a relevant source of law, is undesirable. For international courts and tribunals to wilfully deprive themselves of this potentially fruitful source of inspiration and guidance on issues of evidence and procedure is unnecessarily isolationist and potentially harmful to international law as a discipline more generally.