Introduction

This chapter explores which factors drive the diffusion of environmental policy innovations. Some central assumptions made by diffusion research to date will be challenged by empirical findings taken mainly from an exploratory research project. Empirical data related to the adoption of twenty-one basic environmental policy innovations in forty-eight countries over a time period of fifty years was collected and discussed in the context of theoretical considerations and various case studies.

The chapter begins with a discussion of the conceptual distinction between diffusion and other mechanisms of convergence. There then follows a discussion of factors that may have a crucial impact on the patterns of diffusion. Within this section, interrelations with other types of global or regional governance are discussed. This includes both special features of the EU framework as well as the impact of global norms. The chapter proceeds to discuss the restrictions in the diffusion process, which heavily depend on innovation characteristics and national capacities to innovate. The chapter's main intention is to shed some light on the complex interplay of factors affecting diffusion patterns. In doing so it provides several points of departure for new research questions that are hoped to inspire the scientific debate on globalisation and policy convergence.

Diffusion as distinct mechanism of convergence

Comparative policy analysis has revealed the phenomenon that national environmental policy patterns are becoming similar. This observation immediately evokes the question of the nature of these similarities.