The Ethics and Empirics of Double Hatting

Abstract

Is it time to end the practice of double hatting in international adjudication? In this ESIL Reflection, we examine the practice of double hatting in the specific context of international investment arbitration. We ask three questions: how widespread is the practice; when is it a problem; and what can be done? In doing so, we introduce and develop new empirical findings but also make links between investment arbitration and broader practices in international adjudication.