Proportionality, Reasonableness and Standards of Review in International Investment Law and Arbitration

By Valentina Vadi, Published by Edward Elgar, April 2018

The book examines the merits and pitfalls of arbitral tribunals’ use of the concepts of proportionality and reasonableness to review the compatibility of a state’s regulatory actions with its obligations under international investment law. Investment law scholars have given greater attention to the concept of proportionality than to reasonableness; this book combats this trajectory by examining both concepts in such a way that it does not advocate one over the other, but instead enables the reader to make informed choices. The author also explores the intensity of review as one of the main tools to calibrate the different interests underlying investor–state arbitrations. Available at