The Role of Proportionality in International Investment Law and Arbitration: A System-Specific Perspective

Abstract

In this article, we examine the place of proportionality and related tests in international investment law and arbitration by looking specifically at the challenges faced by this field on applying proportionality coherently and consistently. We also assess where proportionality has been used in international investment law and arbitration. We argue that a sound appreciation of proportionality in international investment law requires taking into account the inherently imbalanced conception of international investment agreements, the incoherence of the international investment law regime, and the ad hoc dispute settlement method tasked with applying and interpreting a variety of imprecise and diverging norms. Therefore, international investment law and arbitration have not developed an institutionalised approach towards proportionality. Since investment agreements and international investment arbitration form a rather incoherent collective of cases and, as a result, have not developed a single or uniform approach towards proportionality, there is a tendency to individually approach cases.