How new quality productive forces reduce carbon emission intensity: a mediated-threshold analysis from China

Against the backdrop of China’s “dual carbon” goals, new quality productive forces (NQPF) have increasingly been regarded as an important driver of green transformation and development upgrading. While recent studies have begun to examine whether NQPF can reduce carbon emission intensity (CEI), existing research has adopted different approaches to measuring NQPF, and less attention has been paid to whether its carbon-reduction effect operates through the broader transformation of development quality and under what energy-use conditions this effect becomes more pronounced. Using panel data for 30 provincial-level regions in China from 2013 to 2022, this study constructs an entropy-weighted multidimensional index of NQPF and employs a mediated-threshold analytical framework combining two-way fixed effects models, instrumental variable estimation, mediation analysis, and panel threshold regression to investigate the transmission mechanism and boundary conditions of the NQPF–CEI relationship. The results show that NQPF significantly reduces CEI, with the benchmark coefficient estimated at −0.186. More importantly, high-quality economic development (HQED) serves as a significant partial mediating channel: the Bootstrap results indicate that the indirect effect is statistically significant and accounts for 41.47% of the total effect. In addition, the carbon-reduction effect of NQPF exhibits a nonlinear threshold pattern with respect to energy consumption intensity (ECI). When ECI exceeds the threshold value of 0.2398, the negative effect of NQPF on CEI is significantly strengthened, whereas the effect is not statistically significant below this threshold. The heterogeneity analysis further shows that the carbon-reduction effect is more pronounced in non–carbon trading pilot regions, renewable energy–abundant regions, and less-developed regions. These findings suggest that the contribution of this study lies not merely in reconfirming the direct carbon-reduction effect of NQPF, but in identifying its system-level transmission through HQED and its conditional dependence on regional energy-use characteristics. The study provides new evidence for understanding how productivity transformation, development-quality upgrading, and differentiated low-carbon transition interact in the Chinese context.