Delineating policy mixes: Contrasting top-down and bottom-up approaches to the case of energy-storage policy in California

In the light of pressing societal challenges such as climate change and resource scarcity, scholars are increasingly interested in studying policy mixes in the context of sustainability transitions. However, despite numerous conceptual advances and empirical insights, researchers still lack universal criteria or accepted heuristics for delineating policy mixes in these complex policy spaces. We address this gap by conducting an extensive review of the literature, synthesizing best practices, and developing an analytical framework that provides researchers with two archetypical methodological approaches. The top-down approach builds on the idea that the elements of a policy mix originate from an overarching strategic intent. By contrast, the bottom-up approach starts from the definition of a focal impact domain that is affected by a range of policy instruments. For each approach, we outline a systematic analytical procedure, then implement it to scrutinize how policy affects the emerging technological domain of energy storage in California. We find that each approach has particular advantages that render it useful for certain policy mix analyses. Discussing how researchers may choose between the two approaches or leverage their complementarities, we seek to provide the basis for a consistent research program building on the policy mix framework.