The term ‘attribution’ refers to the means by which it is ascertained whether the State is involved in a dispute governed by international law. The notion of attribution is primarily used to determine if the State is responsible for the wrongful conduct of persons or entities with links to the State. In the context of international investment law, the exponentially growing arbitration jurisprudence arising from international investment agreements (IIAs), especially bilateral investment treaties (BITs), reflects the extent and risk of attribution determined in investment relationships that often involve State enterprises. This book, the first in-depth study of the uses of attribution in international investment law, provides a deeply informed analysis of the treatment of attribution in applicable legal instruments and investment arbitration jurisprudence worldwide. The analysis responds to such questions as the following: - When is a conduct attributable to the State for the purposes of its responsibility under international investment law? - What legal instruments govern the question of attribution under international investment law? - In what circumstances is the State the proper party to a contract entered into by a State-owned enterprise with an investor protected by an investment treaty? - How can State policymakers minimise their international law responsibility within the existing framework of attribution in international investment law? - How can investors maximise their protection within the existing framework of attribution in international investment law? Also covered are the procedural treatment of attribution by investment tribunals, explication of such broad-brush wordings as ‘elements of governmental authority’ and ‘under the direction or control’, and the impact of the rise of State-owned enterprises as investors. Ongoing and future trends in the jurisprudence are also taken into account. A one-stop reference on the question of attribution in international investment law, the analysis extracts identifiable commonalities among instruments and rulings, turning them into useful practice tools. This book will prove invaluable for practitioners advising States or investors in investment disputes. More generally, this book will be welcomed by arbitrators, in-house counsel for companies doing transnational business and international arbitration centres, as well as by academics in international arbitration.