Robustness tests.

This study uses the non-expected SBM-DEM model of factor input-output to measure the green manufacturing efficiency of 274 cities at prefecture level and above in China. The relationship between digital economy and green manufacturing efficiency is analysed on this basis. It is found that the current coupling coordination between digital economy and green manufacturing efficiency is low overall, and there are obvious regional differences. And the digital economy has a significant positive impact on the green manufacturing efficiency of the region and the neighbouring regions, so the digital economy has a radiation effect on the green manufacturing efficiency. Among them, industrial agglomeration plays part of the mediating effect. Based on this conclusion, the following policy recommendations are proposed: first, accelerate the development of the digital economy to stimulate the new kinetic energy of urban green development. Second, implement differentiated development strategies, focusing on the leading role of green advanced cities. Third, deepen the convergence of industries and smooth the channels for green urban development.本研究采用要素投入产出型非期望产出SBM-DEM模型，对中国274个地级及以上城市的绿色制造业效率进行测算。在此基础上，剖析数字经济与绿色制造业效率之间的作用关系。研究发现，当前数字经济与绿色制造业效率的耦合协调度整体偏低，且区域差异显著；数字经济对本地区及周边地区的绿色制造业效率均存在显著正向影响，即数字经济对绿色制造业效率具有辐射带动效应。其中，产业集聚发挥了部分中介传导作用。基于上述研究结论，本文提出以下政策建议：其一，加快数字经济发展，激活城市绿色发展新动能；其二，实施差异化发展战略，突出绿色发展先进城市的示范引领作用；其三，深化产业融合协同，畅通城市绿色发展的传导路径。