While international relations scholars use a variety of both quantitative and qualitative methodological approaches, the relative frequency of those approaches differs significantly across different parts of the discipline. For example, at least since the 1960s quantitative approaches have been widespread in the study of interstate conflict, and a great number of large-n databases have been constructed to aid the quantitative study of war. In contrast, research on international environmental regimes has been heavily dominated by qualitative approaches, especially case studies, and only a handful of large-n databases are available for analyzing the impact of institutional design on the performance of international regimes.

It is, therefore, a major event when three giants in the field of regime analysis publish a joint book introducing a new large-n database, called the International Regimes Database (IRD). The result of a decade and a half of data collection and accompanied by a CD-ROM containing the database itself, this book is an extremely impressive and important addition to the existing literature on international environmental regimes.

Of course, welcoming a new large-n database is not equivalent to saying that quantitative research is always (or even generally) superior to qualitative research. For example, it has recently been suggested that because of the strong focus on quantitative approaches in the democratic-peace literature, major conclusions from this literature rest on somewhat shaky foundations. But just as predominance of quantitative approaches might entail problems, so can predominance of qualitative approaches.

As a relational database, the IRD enables the user to compare records on various aspects across a number of international environmental regimes. The records are coded using a single set of concepts, definitions, and scales. The construction of the database relied heavily on expert coders, who were asked to respond to questions “only when they felt sufficiently knowledgeable to answer them with confidence” (p. 58).

The book is organized into six chapters. Chapter 1 provides an account of the achievements of regime research, outlines some of the major challenges ahead, and clarifies how the authors intend the IRD to help us meet those challenges. Chapter 2 explains the architecture of the IRD, including its case structures and the coding procedures used. Chapters 3 through 5 apply the IRD in order to analyze selected research questions relating to regime performance. Chapter 3 considers the sources of compliance with regulations provided by international regimes. Chapter 4 maps the impact of decision rules and compliance mechanisms on regime effectiveness. Chapter 5 analyzes the relationship between programmatic activities and the scope for consensual knowledge in regimes, and it considers whether successful problem solving in an environmental issue depends on the growth of consensual knowledge about causes. Finally, Chapter 6 offers some major conclusions and provides directions for future research.

Chapters 3 through 5 are interesting not only in demonstrating how the IRD might be used in practice. They are also helpful in that they provide in-depth analyses of research questions that are at the very core of regime analysis. Moreover, the conclusions are often interesting in their own right. For example, in Chapter 3 the authors find that “neither the shallowness argument of George Downs, David M. Rocke and Peter N. Barsoom (1996) nor the management approach of Abram Chayes and Antonia Handler Chayes (1995) can explain patterns of compliance with international regimes” (p. 110). They go on to argue that “adequate and even impressive rates of compliance with international environmental rules occur when appropriate incentive mechanisms are coupled with juridification, participation on the part of transnational NGOs [nongovernmental organizations] in the rule-making process, and a responsive approach to the development of compliance mechanisms over time” (p. 112).

Similarly, in Chapter 4 they conclude that, contrary to conventional wisdom, the widespread use of decision making by consensus or unanimity does not in general make international environmental regimes ineffective problem solvers. On the contrary, “77.9 percent of the cases featuring some form of consensus resulted in the fulfillment of goals,” and “the coders judged the regime to have had a large causal influence in 73.8 percent of the cases where goals were fulfilled” (pp. 187–88). Also, the fulfillment of goals is often good despite the fact that relatively few environmental regimes have potent mechanisms for enforcement (through threats and punishment): “Enforcement is simply not a prominent feature of efforts to promote compliance with international environmental regimes” (p. 189).

Finally, in Chapter 5, the authors reach the conclusion that “the growth of knowledge resulting from a regime's programmatic activities does not translate automatically into greater success in the realm of problem solving” (p. 224). This should serve as a caution to those who believe that successful problem solving in the realm of (say) climate change will follow once a consensus has been reached on the nature and causes of the problem. In my own experience, this misunderstanding is quite widespread, especially among scholars from the natural sciences.

Because of the extensive use of expert judgments in the collection of data, the IRD may be said to incorporate much of the accumulated knowledge of the international regimes research community. Many will rightly consider this to be a major strength of the IRD. However, one might wonder if it may also be a weakness in certain respects. One purpose of constructing a large-n database should be to provide a quantitative corrective to results obtained by qualitative research in the field. If this is accepted, should we not strive to collect data independently of the findings of that qualitative research?

This tiny question mark, however, certainly cannot overshadow the fact that the book is a tremendous source of knowledge and a great addition to the existing literature on international regimes. It will also serve as a great source of inspiration for other scholars who would like to develop large-n databases on international regimes and their performance. Analyzing International Environmental Regimes could well become the most oft-cited work in the field of regime studies in the next decade.