Regional Integration and National New Quality Productive Forces: Evidence from the Beijing–Tianjin–Hebei Region

This study integrates a multi-regional input–output model, structural decomposition analysis, a coupling coordination model and gray relational analysis within one framework. It examines the relationship between the Beijing–Tianjin–Hebei (BTH) region’s participation in national economic circulation (NEC) and national new quality productive forces (NQPFs). The results show that China’s NQPF index rose from 0.02 to 0.31 over 2012–2020, with the means of labor making the largest contribution, while growth in green and efficient productivity remained limited. BTH’s participation in NEC exhibited a U-shaped pattern, with the inflection point coinciding with the implementation of the Coordinated Development Strategy in 2015. The consumption effect became the largest contributing component after 2015, whereas the value-added and spillover effects made negative contributions in some periods. Coupling coordination between the NEC embedding system and the national NQPF system shifted from imbalance toward high-quality coordination and strengthened after 2015. Gray relational analysis identified industrial value-added growth and consumption upgrading as the components most strongly associated with the NQPF index, whereas the multiplier and investment effects showed the weakest associations.