From regional integration to global insights: spatial dynamics of green productivity and coordinated development — evidence from the belt and road initiative

New Quality Productive Forces (NQPF) refers to the shift in economic structure from factor-driven extensive growth to an innovation-intensive production system. This paper quantifies it from six dimensions: technological productivity, innovation capacity, digital industrialization, industrial digitalization, environmental productivity, and resource efficiency. The study focuses on 18 provinces along China’s Belt and Road Initiative (BRI), covering data from 2001 to 2023. An economic-energy-environment-society (3E-S) framework is introduced, using entropy to measure the coordinated development level of each subsystem and spatial Durbin model (SDM) to capture spatial effects. The results show that, overall, provinces are transitioning from low-level to high-quality development, but the energy subsystem is progressing slowly, and the environmental subsystem is showing significant fluctuations. The spatial effect decomposition results do not conform to the expectation of mutual benefit and win-win outcomes—the production model oriented towards technological innovation and resource conservation may have certain negative impacts at the provincial level and also have negative spillover effects on neighboring provinces. This phenomenon indicates that the current efficiency orientation is triggering more implicit competition than cooperative win-win situations between regions. The above findings have certain reference value for policy making, alleviating structural contradictions, and promoting coordinated development along the Belt and Road.