Policy evolution through coherence, consistency and alignment: the Shenzhen low carbon policy case

Ideally policies are characterised by alignment between goals and instruments, coherence of the former and consistency of the latter. However, in practice policy mixes are merely patched up to solve problems, influencing how policy evolves over time, typically generating increased policy complexity. It remains unclear how policy goal coherence, instrumental consistency, and goal-instrument alignment influence the long-term evolution of low-carbon policies. To address this, this study analyzes the characteristics of low-carbon policy evolution in Shenzhen City (1994–2022) and employ a quantitative longitudinal research design to examine these influences. Overall, policy evolution was characterized by gradual increase in policies with peaks in 2012 and 2021, leading to policy accumulation with increasing policy subdomains. This was in part due to Shenzhen City serving as a national low carbon pilot zone and local government responding to national government programs. Policy evolution entailed a large variety of policy goals and instruments, with policy goals evolving rather flexibly with new goals replacing old ones, while policy instruments developed more incrementally leading to replacement, conversion but also to cases of policy layering. We identified the key factors driving evolution of low-carbon policies, including the city's strategic positioning, the focus of (local) leadership, and the city’s response to national policies. Moreover, a fairly balanced distribution in policy dynamics was observed; this concerned a good fit (replacement) and a poor fit (conversion and layering) between new policies and existing policy mixes. Additionally, policy dynamics varied across and within subdomains.