Tracing actors in policy mixes for transitions: A systematic literature review and insights from policy process theories

• Reviewing actor conceptualisations in policy mixes shows they remain often implicit. • We link actor conceptualisations from the ACF and MSF with policy mixes. • Policy brokers rather influence policy mix characteristics than elements. • Interactions between policy entrepreneurs give insights into policy mix development. • We propose a more actor-centred policy mix approach. In transition studies, the concept of policy mixes gains traction. Despite the crucial role actors play in both transition studies and policy processes, it is surprising that explicit conceptualisations of actors within the policy mix concept remain scarce. This paper addresses this gap by conducting a systematic literature review to assess how existing contributions in transition studies conceptualise actors within the concept of policy mixes. We find diverse yet predominantly implicit conceptualisations of actors in the literature. We argue that policy process theories offer considerable potential to strengthen actor conceptualisations within policy mixes. Consequently, we present and discuss actor conceptualisations inspired by two well-established policy process theories: the Advocacy Coalition Framework and the Multiple Streams Framework. A refined theoretical understanding of actors in this field enhances our ability to discern their roles and actions in the politics of policy processes towards policy mixes for sustainability transitions.