Legal Reasoning of International Investment Tribunals: A Typology of Egregious Failures

From a scholar, practitioner and policy-maker perspective, at the heart of the recent taking of centre stage of international investment law stand without doubt the several hundreds decisions rendered by investment treaty tribunals. Despite the fact that there is no general duty to make investment treaty decisions fully public, the great majority of decisions rendered in (at least known) investment treaty arbitrations appears to make its way into the public domain. The important role played by publicly available investment decisions in terms of internal and external legitimacy revolves around the reasoning underlying such decisions. By exploiting the public availability of investment treaty decisions, the aim of the article is to contribute to the strengthening of the international investment system by sketching three types of egregious failures in the reasoning underlying some of these decisions: (a) misuse of precedent, (b) lack of internal consistency and (c) minimalism. The claim is that these three failures are ‘egregious’ in the sense that they represent instances where the investment tribunal's reasoning is manifestly ‘contradictory’, ‘inconsistent’ or ‘practically non-existent’.