Understanding the multisectoral and multiregional cooperation which coordinates the relationship between different government actors and integrates their policies is essential to effectively address increasing regional air pollution. Although the literature on effects of polices is rapidly expanding, little is known about the actual extent of policy linkage of multisector and multiregion, resulting in policy conflicts and duplications. Using 13486 policy documents in China from 2000 to 2018, we combine machine learning methods with social network analysis to investigate the policy content and linkage in central departments and local departments. We find that, firstly, the coordination of central departments is constantly improving, mainly focusing on the Comprehensive Control and the Publicity Guide, with little attention to market-oriented measures. Secondly, since local governments have similar policy foundations in Emergency Management, Total Amount Control, Dust Control, and Moving Pollution Control, they are able to cooperate in these aspects, even when there are differences in local regulations. This paper provides suggestions for the further coordination of the central government, as well as the direction of policy integration for local governments.

The transportation sector has a significant impact on the synergistic reduction of CO2 and pollutants. Using a structural path decomposition, we reveals the direct and embodied CO2 and NOx emissions from the transportation sector triggered by key supply chain pathways. Meanwhile, the emission abatement potential and economic costs of 33 vehicle specific abatement technology options are analyzed based on the input-output analysis for life cycle assessment. The results show that most of the vehicle technology options can reduce CO2 and NOx emissions while saving economic costs. Among these technologies, both the pure electric technology for passenger cars and the parallel hybrid technology for heavy-duty trucks have high abatement potential. Compared to costly pure electrification technologies for passenger cars, parallel hybrid technologies for heavy-duty trucks offer the highest economic benefits as well as a better driving mileage. Therefore, hybrid heavy-duty trucks will be a more comprehensive solution in the near future.