Unleashing the convergence between SDG 9 and SDG 8 towards pursuing SDGs: Evidence from two urban agglomerations in China during the 13th five-year plan

Cities play a pivotal role in China's sustainable economic progress, serving as focal points for various developmental elements. This study offers a novel perspective, delving into two crucial dimensions of urban advancement: industrial infrastructure and economic growth. This research assesses the sustainable development efficiency of 36 cities within the Yangtze River Delta urban agglomeration (YRDUA) and the Pearl River Delta urban agglomeration (PRDUA), using specific indicators aligned with SDG9 and SDG8. To conduct this evaluation, the study employs the Meta-Frontier Window Network DDF Data Envelopment Analysis considering both the stability and enhancements in urban sustainable development efficiency over a five-year policy span. The key findings are as follows: 1) Urbanization emerges as a driver of sustainable development efficiency. However, while Shenzhen, Dongguan, and Zhuhai have attained optimal levels, their internal efficiency stability remains a concern; 2) During the 13th Five-Year Plan, Nantong, Changzhou, and Wuxi showcased significant performance improvements. In contrast, Jiangmen experienced a notable decline of 64.72%; 3) Focusing on subsystems, the Resilient Industrial and Infrastructure Subsystem displays superior efficiency compared to the Sustainable Economic Growth Subsystem. Yet, it's essential to note that neither subsystem has achieved optimal efficiency across most regions; 4) Geographically, the urban sustainable efficiency of YRDUA appears evenly distributed, with ample room for improvement in most cities. In contrast, PRDUA demonstrates an efficiency increase from its periphery to its core. Through this comprehensive exploration, the study provides valuable insights into the intricate relationship between urbanization, sustainable development efficiency, and regional disparities. •Developed comprehensive indicators tailored to China's situation referring to the SDG framework.•A novel model addressing the efficiency and internal stability of different periods is proposed.•Urbanization enhances the efficiency, yet the promotion of internal stability is unobvious.•Setting a five-year plan is an enduring and effective policy.