How do international processes, actors and institutions contribute to domestic policy change and cross-national policy convergence? Scholars in the fields of international relations and comparative politics have identified a wide array of convergence mechanisms operating at the international or transnational level. In order to categorize this wide array of possible causes of policy convergence, we propose a typology of three broad classes of mechanisms: (1) the co-operative harmonization of domestic practices by means of international legal agreements or supranational law; (2) the coercive imposition of political practices by means of economic, political or even military threat, intervention or conditionality; and (3) the interdependent but uncoordinated diffusion of practices by means of cross-national imitation, emulation or learning. We illustrate and substantiate this claim through the empirical analysis of the international spread of three different kinds of policy innovation: national environmental policy plans and sustainable development strategies, environmental ministries and agencies, and feed-in tariffs and quotas for the promotion of renewable electricity.

During the 1990s, a new regulatory pattern in domestic environmental policy making emerged. This pattern is largely a result of policy diffusion. In the absence of formal obligations, regulatory instruments that have been communicated internationally and were already being practiced elsewhere were voluntarily emulated and adopted by policy makers. While the international promotion of regulatory instruments often facilitated their diffusion, the instruments’ characteristics determined the extent and speed by which regulatory instruments spread across countries. The voluntary adoption of regulatory instruments cannot be exclusively explained by the rational motivation of policy makers to improve effectiveness. In addition, they were motivated by concerns of legitimacy and perceived pressure to conform with international norms.

In a context of multiple crises, the European Union’s climate and energy policies have become highly politicized and contested. Based on a comparative study of renewable energy policies in ten EU member states, and adopting a circular view of policy change and Europeanization to account for overlapping sovereignty claims between the national and the European level, this article unravels the authority debates over successive rounds of negotiation, adoption, and implementation along three EU directives. Following an exploratory process-tracing method, we investigate how policymaking authority originally delegated to the EU becomes contested by the member states and how these authority conflicts are managed. We find that the Europeanization of renewable energy policy is accompanied by an issue-specific renegotiation of authority between the EU and its member states which, in times of crises, can trigger instances of de-Europeanization and even a partial weakening of European integration in this policy domain.

While the first part of the article focuses on the possible advantages of strategic and integrative planning in environmental policy, the second part looks at existing national planning approaches in OECD countries, underlining important differences and similarities, and attempting a preliminary evaluation of three national environmental policy plans. On this empirical basis the article represents an attempt to systematise existing approaches and to draft model stages in environmental planning.