Articles

• Kulick, Andreas

Abstract

A quantitative and qualitative study of international investment arbitration case law employing the concept of estoppel reveals investment tribunals’ inconsistency with regard to the concept’s requirements. This article discusses possible reasons why tribunals often deviate from what appears to be the established view in the jurisprudence of the International Court of Justice and in international law scholarship and why they do not explain their preference for one view or the other. In fact, the often striking lack of reasoning in this respect begs the question regarding the order of approach chosen and the outcome produced. In the interest of doctrinal and jurisprudential consistency, arbitrators should be more transparent with respect to their choice of view and their reasons for choosing one over another. This will sharpen the concept of estoppel both in international investment law, in particular, and in public international law, in general.