104 Effective Implementation of International Environmental Norms Jon Birger Skjærseth, Olav Schram Stokke and Jørgen Wettestad Soft Law, Hard Law, and Effective Implementation of International Environmental Norms • Jon Birger Skjærseth, Olav Schram Stokke and Jørgen Wettestad Introduction The study of institutional interplay in international environmental governance is increasingly pervasive. 1 So far, however, little systematic attention has been given to an important part of this ªeld—the interaction between soft law and hard law. Contributions on soft and hard law in international governance tend to discuss these types of law separately, or as an evolutionary process from soft to hard law in one issue area or within one institution. 2 This article expands the study of soft and hard law to the interplay between different institutions operat- ing in the same problem-area, such as multinational environmental agreements and the European Union. By doing so, we explore and identify mechanisms that have received scant attention in the study of the relationship between different types of law and effectiveness. “Soft law” refers to international norms that are deliberately non-binding in character but still have legal relevance, located “in the twilight between law and politics.” 3 Important examples are resolu- tions by international organizations and international plans of action or codes of conduct. The essence of “hard law” is legally binding obligations. Other dimensions sometimes considered when evaluating the “hardness” of legal commitments are precision—unambiguity with respect to the conduct required, authorized, or proscribed—and delegation of authority to third parties for inter- preting and implementing the law. 4 This article explores the validity of two propositions on the relationship between soft law, hard law, and institutional effectiveness. 5 The ªrst proposition 1. For recent contributions, see Oberthür and Gehring 2006; Young 2002; and Stokke 2001. 2. See e.g. Abbott and Snidal 2000; Thürer 2000; and Sand 1991. 3. Thürer 2000, 452–454. 4. Abbott and Snidal 2000, 421. 5. The article draws on certain parts of material published in Skjærseth 2006; Stokke and Coffey 2006; and Wettestad 1998, 2002, 2004. Global Environmental Politics 6:3, August 2006 © 2006 by the Massachusetts Institute of Technology