In a globalized world, national policies on technology, health, finance, and other issues demonstrate a tendency toward convergence. The environment, in particular, illustrates convergence in politics, policy, and legal regulations across states. As environmental policy-making has proliferated since the 1980s, domestic environmental policies across countries have increasingly aligned with one another.

In Understanding Environmental Policy Convergence, the authors analyze the driving forces of environmental policy convergence, asking why policies emerge, are adopted, and converge, in the context of national environmental policy. The book presents the findings of a qualitative analysis of individual processes of policy change, building off a previous quantitative study. That previous study analyzed the development of forty environmental policy items in twenty-four countries at four points in time (1970, 1980, 1990, 2000), and suggested that “convergence appears to be the rule in the environmental field over the past decades, and non-convergence rather the exception” (p. 10).

This book successfully combines the field of comparative policy analysis, which focuses on the national determinants of policy change, with the study of international relations, which looks at international dynamics. The authors examine international patterns of environmental policy change and convergence on seven environmental issues: contaminated sites, industrial discharges into surface water, noise emission from lorries, motorway noise pollution, leaded petrol, as well as the introduction of the principles of precaution and sustainability.

The research is guided by the hypothesis that international economic and institutional embeddedness matter. Focusing on a selection of four countries with different levels of institutional and economic embeddedness (the Netherlands, France, Hungary, and Mexico), the authors seek to elucidate how the countries’ dependence on international trade and their memberships in European and international organizations play out in the processes of policy convergence. The authors discuss the roles of international harmonization, transnational communication, regulatory competition, imposition, and parallel problem pressure in shaping and defining the scope, degree, and direction of environmental policy convergence.

International harmonization involves states complying with legally binding regulations related to international or supranational law norms. Transnational communication leads to convergence through the exchange of information, and can involve lesson-drawing, transnational problem-solving, international policy promotion, or emulation. Regulatory competition drives convergence when countries, and industries within these countries, adjust to nationally authorized standards of production processes and tradable products. Convergence by imposition happens through the power of supranational organizations or states that demand the adoption of certain environmental policies and rules in exchange for an approval of membership in common markets or politico-economic unions like the European Union. Finally, a parallel problem pressure mechanism explains international policy convergence independent of international dynamics. This hypothesis is based on the expectation that “the existence and/or perception of similar problems may lead to similar domestic policies in different countries without any notable influence of international factors” (p. 17).

This book confirms previous arguments about policy convergence and its scope. For example, as is posited by those who study Europeanization, the authors here indicate that domestic actor constellations, institutional structures, and traditional policy discourse can lead similar international impulses for convergence to take different shapes. The book also supports the idea that environmental convergence represents an upward trend in regulatory stringency.

The authors conclude that transnational communication and regulatory competition are the most important mechanisms of convergence, and that harmonization is dependent on the prior competitive or communicative dynamics. Moreover, they do not find support for the claim that powerful states widely use imposition as a mechanism of environmental policy convergence.

Besides contributing to improving our understanding of how the various mechanisms of convergence work in practice, this book also reveals methodological challenges in accounting for the parallel problem pressure mechanism. Because policy entrepreneurs working at the domestic level may also be active participants in transnational communication via international organizations or epistemic communities, it is not always easy to identify the driving forces of policy convergence—in other words, whether convergence is purely domestic.

Overall, this book offers richly structured information on the processes and mechanisms of policy convergence regarding selected environmental issues in four countries. As such, it enables a better understanding of the different mechanisms utilized in policy convergence and policy shifts, domestic and international. However, its explanations of the chosen mechanisms of policy convergence are, at times, confusing. A clearer distinction between convergence of the content of environmental policies and similarity of the organizational forms and practices of policy implementation after convergence would be helpful. Occasionally, it can be difficult to understand what the authors mean by the different mechanisms identified.

This book has implications beyond this issue area. For example, highlighting ways in which economic openness, intensification, and institutionalization of international contacts happen simultaneously with the introduction of environmental regulations provides useful insight into how international processes and changes interact. The argument could have been made even more relevant to the field of international political economy if the authors had broadened their questions, examining how purely environmental issues become politicized and what implications that process has for policy convergence. Nevertheless, the authors demonstrate the usefulness of supplementing quantitative convergence analysis with in-depth case studies that can illuminate unquantifiable or previously unknown factors.