Sometimes referred to as “private authority,” governance by nonstate actors has attracted considerable scholarly interest in recent years. Focusing on environmental governance in general and climate governance in particular, Rethinking Private Authority has an ambitious point of departure, asking when and why private actors perform regulatory roles in global environmental politics.

Jessica Green defines private authority as “situations in which nonstate actors make rules or set standards that other relevant actors in world politics adopt” (p. 29). She “disaggregates” the concept into “delegated authority,” which is equivalent to a traditional principal–agent relationship, and “entrepreneurial authority,” which is similar to the traditional understanding in the literature of private authority as governance without government.

Green proposes “a complete theory” that explains not only when private authority will emerge but also “what type of private authority will emerge” (p. 40); she develops a functional supply-and-demand account of the emergence of private authority. In this model, she explains the demand for private authority by its potential benefits: reduced transaction costs, enhanced credibility of commitments, first-mover advantage, and improved reputation. All these benefits require that the private actors possess expert knowledge, which is the potential supply of private authority in Green’s model. Finally, the model predicts that delegated authority will emerge when there is a strong focal institution (such as an international regime) and shared preferences among powerful states, whereas entrepreneurial authority will emerge when there is no focal institution (or a weak institution) and powerful states have heterogeneous preferences.

Green begins her empirical study of private authority with a quantitative examination of a century of multilateral environmental treaties, asking how often states delegate to private actors, and for what tasks. She finds that, while the total amount of governance is increasing, delegation of governance functions to private actors is relatively rare; further, among all governance functions delegated to private actors, states are least likely to delegate rule-making authority. If states rarely delegate rule-making authority to private agents, is delegated authority a form of private authority, as Green defines it? Her findings seem to contradict her claim that delegated authority is an important but neglected form of private authority. Equally important, delegated authority and entrepreneurial authority appear to be based on different governance logics, making it problematic to label both forms as private authority. It might be preferable to reserve the concept of private authority for instances in which no form of state delegation is involved.

Green then examines the quantitative extent of entrepreneurial authority in the area of transnational environmental policy, including data on all known forms of relevant civil regulations from 1954 to 2009. She finds that entrepreneurial authority has been growing quickly, particularly in the last decade, and that this form of private authority appears to be emerging in areas that require preexisting expertise and have relatively weak focal institutions governing them, as predicted by her model. She also finds that most civil regulations require third-party certification, and that there is a growing number of “amended” civil regulations, whereby such regulations “adopt some part of existing private rules” (p. 79).

This examination is a useful effort at quantifying the growth and extent of private standards, but the coding of data can be questioned. Green mentions the Marine Stewardship Council specifically as an example of an amended standard, because it is purported to draw on some existing form of civil regulation—whereas it in fact only drew on intergovernmental rules and standards when it was created (in particular the FAO Code of Conduct for Responsible Fisheries). If this example is representative of the coding of de novo versus amended private standards, there might be problems with the coding of the data material.

The book also includes a chapter on delegated authority in the Clean Development Mechanism (CDM) and a chapter on the Greenhouse Gas (GHG) Protocol as entrepreneurial authority. These are well-executed and pertinent case studies, demonstrating Green’s expertise on carbon standards and climate governance. The cases confirm her supply-and-demand account of private authority and the form it takes as either delegated authority (as in the case of the CDM) or entrepreneurial authority (as in the case of the GHG Protocol). However, these confirmations of Green’s theory might have made it difficult to see the shortcomings of the theory.

Green recognizes that private authority implies consent from those who adopt rules, but she fails to see the interests and power struggles involved in nonstate governance. No examination of private authority can be comprehensive if it does not take into account the quest for power within multi-stakeholder programs, among various private rule-makers, and between private and public authorities. Research has identified NGO targeting of big corporations, transnational activism, and industry responses as factors critical for explaining the emergence of different forms of private authority. Green recognizes some of this research, but her supply-and-demand account of when and how private authority emerges has no room for such factors. In the absence of a consideration of power, interests, and political contestation, a theory of private authority cannot be complete.

Green relatedly predicts that private authority will emerge as either delegated or entrepreneurial, but she fails to take seriously the wide variation in the forms of private authority. Questions addressed in research include: When will multi-stakeholder authority emerge, and when will industry-dominated authority emerge? When will third-party certification schemes emerge, and when will industry codes of conduct emerge? How can we explain variation in the stringency and policy focus of nonstate governance programs within and across sectors? Green’s theory and analysis do not offer any answers, despite the attention paid to such questions in recent research.

These shortcomings should not overshadow the fact that Green has written an engaging, comprehensive, and reflective account of the emergence, growth, and extent of private authority. Her book makes a significant contribution to our understanding of nonstate governance, and provides a successful combination of rigorous quantitative analysis and in-depth case-study research. Rethinking Private Authority is essential reading for all who are interested in the emergence and spread of nonstate governance in global environmental politics.