Transboundary impacts on SDG progress across Chinese cities: A spatial econometric analysis

The 17 sustainable development goals (SDGs) proposed by the United Nations are currently being implemented by all United Nations member states to achieve sustainability by 2030. Growing transboundary environmental and socioeconomic interactions across different regions can positively or negatively affect the progress towards achieving SDGs; however, these transboundary impacts on SDG progress are rarely studied. This study included 285 Chinese cities as initial survey to assess how inter-city interactions affect cities’ SDG progress based on spatial econometric models. Chinese cities were separated into megalopolises and non-megalopolises. Interestingly, results show that interactions between cities generated synergistic effects to promote the progress of SDG in these cities. On average, a 10% increase in SDG progress of peripheral cities could contribute to a 4.28% improvement in SDG progress of focal cities. In particular, megalopolis cities figured prominently in promoting the holistic achievement of SDGs and regional coordinated development, which exerted an 86.21% stronger synergistic effect than non-megalopolis cities. Additionally, based on a spatial convergence model, results show that there was a converging trend across Chinese cities regarding the SDG performance, suggesting that cities that have been left behind were catching up to cities that have experienced greater progress in achieving the SDGs. These findings provide evidence for Chinese policymakers to broaden solution channels to promote regional coordinated development in spatial thinking instead of treating each region as an independent entity. More efforts are needed to construct well-developed transport and communication networks in vulnerable cities to enhance inter-city synergistic effects.