A Dynamic Assessment of Manufacturing Low-Carbon Transition in the Chengdu–Chongqing Economic Circle: A Set Pair Analysis with State Transition Matrix

In response to global climate change and China’s “Dual Carbon” goals, the transition to low-carbon manufacturing has become a crucial step for achieving high-quality regional development. This study focuses on the Chengdu–Chongqing Economic Circle and constructs a comprehensive evaluation system spanning economic, technological, energy, carbon emission, and environmental dimensions. By applying a dynamic Set Pair Analysis (SPA) model coupled with a state transition matrix, we assess the low-carbon manufacturing performance of eight core cities from 2016 to 2023. The results indicate the following: (1) Strong path dependence characterizes regional low-carbon development, revealing a “Matthew effect” in which leading cities continue to advance while lagging ones face persistent barriers. (2) Cities are evolving into distinct equilibrium patterns: Chongqing is progressing toward full optimization, and Chengdu and Mianyang remain in a high-level equilibrium, whereas Suining and Zigong show signs of long-term low-level lock-in. (3) A three-tier regional structure emerges: Chongqing and Chengdu represent a high-level steady state; Deyang, Mianyang, Yibin, and Luzhou form an intermediate fluctuating tier; and Suining and Zigong constitute a low-level locked tier. (4) The low-carbon transition of manufacturing within the region remains markedly unstable, with cities such as Deyang and Yibin yet to establish steady low-carbon trajectories and remaining susceptible to regression. These findings provide a robust, evidence-based foundation for policymaking aimed at fostering coordinated and sustainable low-carbon development in the Chengdu–Chongqing region’s manufacturing sector.