Assessing the spatiotemporal patterns and drivers of pollutant-carbon reduction synergistic efficiency in the Yangtze River Delta region

As one of China’s leading manufacturing hubs, the Yangtze River Delta Region (YRDR) faces the challenge of jointly reducing pollutant and carbon emissions. This study employs an integrated framework by incorporating methods of super-efficiency slacks-based measure data envelopment analysis, kernel density estimation, social network analysis, and geographical detector to examine the spatiotemporal patterns and divers of pollutant-carbon synergistic efficiency (PCSE) in the YRDR from 2013 to 2021. Results indicate that the PCSE exhibited an upward trend, increasing at an average rate of 0.026 annually and reaching 0.665 by 2021. Notably, post-2018 witnessed accelerated improvement, with an average annual increase rate of 0.060. Spatially, the 27 central cities accounted for 64.7% of the whole regional increment in PCSE. Economically advanced cities like Shanghai and Suzhou (in Jiangsu), maintained persistently high PCSE values and the 14 peripheral cities (e.g., Huainan and Huaibei) remained low. Social network analysis shows enhanced inter-city connectivity, trending towards greater balance and resilience, with Shanghai and Suzhou (in Jiangsu) emerging as pivotal hubs in the network. Technological progress, economic development, and road infrastructure expansion are the primary drivers of PCSE enhancement. These findings underscore the need to enhance inter-city collaborative development, advance industrial restructuring in resource-dependent cities, and prioritize scientific and technological innovation to accelerate synergistic efficiency and support sustainable development.