## 5 Conclusions
### Conclusion of the Paper  
Based on the panel data of 30 provinces in China from 2004 to 2017, this paper analyzes the impact of the APCP Action Plan on _GTFP_[48]. Furthermore, it studies the moderating effects of industrial structure rationalization and optimization on the improvement of the environmental policy on _GTFP_. The following conclusions are drawn:  
(1) The APCP Action Plan can effectively improve the _GTFP_, which indicates that environmental policies can improve the efficiency of resource utilization and reduce the emission of environmental pollutants and thus increase the _GTFP_ by adjusting the industrial structure transformation and optimization among regions and improving the level of green technological innovation.  
(2) The APCP Action Plan policy has heterogeneous effects on _GTFP_ in different pilot regions. The policy has effectively promoted the increase of _GTFP_ in the Pearl River Delta region in southern China, but its impact on the green development of the other two regions is not obvious. It shows that the APCP Action Plan policy has a regional difference in the impact on the _GTFP_.  
(3) In the analysis of the mechanism, by introducing the industrial structure optimization and rationalization as the moderating variables, it is clear to find that the rationalization of the industrial structure can enhance the promotion effect of the APCP Action Plan policy on the _GTFP_.  
In view of the conclusion, this paper puts forward the following relevant suggestions [49]. First, when formulating environmental policies, the government should consider regional differences, adjust measures to local conditions, and set different stage goals according to different pollution sources, rather than rigid policy provisions [50]. Second, the local governments can carry out the trade-off policy promotion work according to the environmental policy and the local development characteristics. On the one hand, the local governments should actively implement the relevant work of the policy and achieve the policy objectives by improving the transformation and optimization of industrial structure [51].  
On the other hand, it is important for them to rationalize the transfer according to the local industrial characteristics without harming the local economic development as far as possible [52]. They should reduce the number of high-pollution and high-emission enterprises, improve the green technology innovation ability, reduce pollutant emissions, and then step into the road of sustainable development [53]. Third, it is essential for local governments to regulate and control environmental policies, promote the coordinated development of regional environment and economy, pay attention to the emphasis on industrial structure transformation and optimization. Moreover, speeding up the transition from primary industry to high output value and low pollution tertiary industry [54], and rationally adjusting the proportion structure of the secondary industry is necessary. All regions should actively eliminate enterprises with backward technology and serious pollution, invest more funds to encourage the inclusion of more high-tech enterprises, and promote the sustainable development of the economy [55; 47; 56].  
**Author Contributions:** [PERSON] and [PERSON] contributed to all aspects of this work; [PERSON] conducted data analysis and wrote the main manuscript text. All authors reviewed the manuscript. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the National Social Science Fund of China (NO. 19 BTJ)049).  
**Data Availability Statement:** The data presented in this study are available on request from the author.  
**Conflicts of Interest:** The authors declare no conflict of interest.