Does pluralistic collaborative governance between governmental and social actors promote urban carbon emission reduction? Evidence from 107 cities of China

The traditional government-dominant environmental governance must undergo a transition to a pluralistic collaborative governance. Existing studies predominantly focus on the cooperation between government and public, rarely involving other social forces together. This study aims to develop methodologies for measuring collaborative governance between governmental and multiple social actors (including public, media and environmental organization) and elucidating its structural characteristics, and investigate how these characteristics impact on carbon emissions. Multi-actor collaborative carbon reduction networks (MACCRN) were constructed for 107 Chinese cities using our proposed methods based on Social Network Analysis (SNA) and multi-source data mining. Their network characteristics were described using both new indicators and conventional SNA indexes. Subsequently, the spatiotemporal evolution of these characteristics were analyzed. Finally, the econometric model and XGBoost with SHAP value algorithm were respectively used to examine the impact mechanism of MACCRN's characteristics on carbon emissions. The main findings include that: (1) MACCRNs differed significantly in the scale and intensity across the 107 Chinese cities. (2) The MACCRNs showed an overall trend towards decentralization, enhanced cooperation intensity, greater involvement of social force, and more balanced participation of various actors. (3) Four network characteristics had significant relationships with carbon emission intensity, with network balance ranking as the top factor. (4) Reducing the network hierarchical structure by decentralization, enhancing network density by engaging more actors and fostering their collaborations, and promoting network balance by participation of various actors helped reduce carbon emission intensity. (5) Cooperative modes with relatively dominant government force or social forces both achieved a reduction in carbon emission intensity. However, unilateral dominance tended to increase carbon emissions intensity. (6) Cities with higher administrative levels consistently outperform those with lower administrative levels. These findings provide valuable reference for the formulation of pluralistic collaborative carbon reduction strategies.