Custom and Its Interpretation in International Investment Law

Volume 2

At first glance, one may think of international investment law as a response to custom (or lack thereof), instead of a field of its application. However, in fact, the opposite is the case. The interpretation and application of customary rules and principles are the bread and butter of international investment law and arbitration. With a diverse range of expert contributors, this collection traces how customary international law is practised in international investment law. It considers how custom should be interpreted and how its rules and principles should be understood and applied by investor-state arbitral tribunals. Raising and addressing vital questions surrounding custom and international law, this collection is a necessary contribution to the scholarship of the theory and history of customary international law and international investment law. This title is also available as Open Access on Cambridge Core.

Panos Merkouris is Professor of International Law at the University of Groningen. He is Principal Investigator of The Rules of Interpretation of Customary International Law (TRICI-Law) project (European Research Council [ERC] grant agreement no 759728). Professor Merkouris is an acclaimed author and has written extensively on the law of treaties, sources and interpretation, most recently coauthoring Treaties in Motion (2020) with Professor Malgosia Fitzmaurice.

Andreas Kulick is Senior Research Fellow at University of Tübingen, Germany. He is visiting professor at the Albert Ludwigs University Freiburg in the winter semester of 2023–2024. He has been a visiting fellow at the Lauterpacht Centre for International Law, NYU School of Law, and the European University Institute. He has written extensively on all aspects of international law, with a particular focus on international adjudication. Also, he regularly advises and represents States in proceedings before international courts and tribunals, including investment arbitration.

José Manuel Álvarez-Zarate is Professor at Externado University of Colombia and Director of the Law and Economics Department where he runs the International Economic Law (IEL) program. He has written extensively on trade and investment matters and practices advising and representing in proceedings before local and communitarian tribunals, including investment arbitration.

Maciej Żenkiewicz is Assistant Professor at Nicolaus Copernicus University in Toruń. He also teaches as a visiting professor at various universities, including Antonio de Nebrija University, Spain; Pontificia Universidad Católica del Perú, Peru; and Xi’an Jiaotong University School of Law, China. He is the author of various articles and monographs.