How can we evaluate the policy mix effectiveness? – A systematic literature review

Although there is much disagreement about the appropriateness, usefulness, and cost-effectiveness of specific policy instruments, there is a consensus across disciplines that a policy mix, not only single instruments, is needed to fully decarbonize the energy system. However, there is no agreement on assessing the effectiveness and dynamic interaction within a policy mix. As a result, we conduct a systematic literature review on existing policy mix evaluation to conceptualize the policy mix analyses from different perspectives, such as environmental economics, policy and innovation studies, and social-technical systems, and understand state-of-the-art ex-ante assessments of the mix as well as current applications/challenges for the empirical analysis. Some common objectives for systematically evaluating the progress of policy mix output are analyzing not only the density (number) of the policies but also their intensity, technological/sectoral specificity, and temporal characteristics (different stages of the energy transition). Ultimately, this review study will broaden the understanding and be a basis for identifying research gaps in empirical studies related to evaluating policy mix effectiveness and dynamic interaction necessary for the energy transition.