INTRODUCTION

This chapter gives an overview of the research design of the project, of the variables under investigation and of the data. Given the central research question underlying this project, convergence of national environmental policies is conceived as the dependent variable. Convergence is observed for twenty‐four countries over a period of thirty years. Policy convergence is measured as increasing policy similarity over time. Policy similarity is investigated with respect to three dimensions of policy: presence‐of‐policy, policy instruments and policy settings. In section 4.2, we specify the operationalisation of and data collection for the dependent variable.

As outlined in chapter 3, the explanatory focus of the project is on three factors as the main independent variables that are expected to account for differences in environmental policy convergence: (1) the degree of interlinkage of countries in international institutions with obligatory potential, (2) the degree of interlinkage of countries in international institutions with communicative potential, and (3) the degree of economic interlinkage, i.e., the extent to which a country is connected with other countries by its trade relations. Moreover, we include further explanatory variables (referred to as ‘other variables’ in chapter 3).