The research question addressed in this research is “How and why do public policies change?”. In order to answer this question, we have presented a definition of policy changes based on Peter Hall' distinction between three orders of change (Hall, 1993), but we have only considered two dimensions of policy changes: the change of policy objectives and the change of policy instruments. We have developed a theoretical framework to explain the policy change and formulated four sets of hypotheses drawing from different approaches of the policy literature. Then, we confronted the research question and the theoretical framework to an original empirical background: the RES-E policy changes in Belgium, Denmark, Germany, the Netherlands and the UK in the period of 1999 to 2004. The empirical research involved in-depth case studies of each country's RES-E policy changes, followed by a systematic comparison of the individual case studies' findings. The comparison allowed us to draw interesting conclusions about the validity and relevance of our theoretical framework and, more generally, about the contribution of the results of our research to the policy literature. Now, in this conclusion, we will summarise the main findings of our research from a theoretical point of view and emphasise the contributions of this research to the policy literature. In addition, we will present the main empirical contributions of our research to the analysis of RESE policies in Europe. And, in the meantime, we will also discuss some normative issues raised by our research for the policy analysts or the policymakers. Policy changes have been analysed from a very pragmatic perspective in this research, with a focus on empirically observable policy objectives (policy targets) and instruments (target groups, incentives and resources of the policy). This definition of policy change proved to be very useful and consistent, especially in a comparative analysis. The distinction between the policy objectives and the policy instruments, following Peter Hall, also proved to be very relevant from a theoretical point of view, as we observed different patterns for the explanation of those two types of policy change, hence the hypotheses explaining the change of policy objective are not the same as the ones explaining the change of policy instrument. Therefore, our comparative analysis shows that it does make sense (and not only empirically) to theoretically distinguish the changes of policy objective and instrument while trying to explain policy changes.
How and Why Do Policies Change? How and why do policies change? The author addresses this question by examining the renewable electricity policies of five European countries (Belgium, Denmark, Germany, the Netherlands, and the UK) over the last thirty years. Employing a comparative approach that is qualitative yet consistent and rigorous, she describes how these countries' policies changed over time, whether incrementally or comprehensively, and shows how those changes may be explained, citing political, economic, social, and technological factors.