Who is leading the methanol price? The roles of international transmission and energy price based on the PLBX model

Driven by decarbonization and energy security strategies, China has emerged as the world's largest methanol market. However, its regional structure and underlying price influence mechanism remain unclear. This study constructs the spatial correlation network of methanol price (MP) in China. Then, a three-stage feature identification model (PCC-LASSO-BO-XGBoost, PLBX) is proposed to elucidate the effects of international market and energy price, with causal relationships further examined using convergent cross mapping. The results show that: (1) MP exhibits a clear core-marginal structure. North, East, and Central China occupy core positions, while Southwest, Northwest, South, and Northeast China remain at the margin. (2) MP in the United States and Rotterdam serve as the key external drivers of China core/marginal markets, with correlations of 42.76%/39.92%. (3) The aggregate impact of energy prices on core/marginal MP reaches 39.88%/37%, where coal and crude oil exert a more pronounced influence than natural gas. (4) Causal analysis further indicates that coal price acts as a dominant shock transmitter, whereas international methanol and crude oil markets function as price-signal resonators through stable bidirectional linkages with China's methanol market. These findings provide an international perspective and multi-method framework for advancing the understanding of MP formation mechanism.