Governing policy experiments in Chinese cities: Lessons on effective climate mitigation

Abstract Policy experiments are crucial for fostering innovation and mitigating risks and can serve as catalysts for transformative changes. This study investigates the governance of policy experiments in China, focusing on how political factors shape their outcomes. It emphasizes the need to consider concurrent trials—related policy trials implemented simultaneously in a locality that can influence outcomes—when selecting comparable cases for analysis. Such consideration is critical, especially when the policy issue spans multiple sectors and the level of difficulty differs across sectors. By comparing five cities engaged in the same three decarbonization pilots between 2010 and 2015, Hangzhou and Xiamen are identified to have had similar initial conditions and goals but achieved divergent outcomes. This research uncovers the critical role of political leadership in achieving varying levels of decarbonization progress and identifies policy coherence with broader local priorities to be the key explanation for continued leadership attention and efforts devoted to decarbonization despite turnover. The study contributes to the literature by addressing the under‐studied impact of political factors and concurrent trials, offering a replicable procedure for future research and practical policy applications.