Measurement and coupling analysis of the efficiency of resource-based treatment of municipal solid waste in Chengdu–Chongqing area

Municipal solid waste (MSW) is crucial for carbon cycle, residents' lives, and green circular economy development, but quantitative research is limited in efficiency and regional synergy. Considering the regional characteristics of Chengdu and Chongqing, this study establishes the input–output indicator system of MSW treatment in 16 cities in the Chengdu–Chongqing area, constructs the Data Envelopment Analysis model and the coupling coordination degree model, and makes an in-depth study on the efficiency and environmental benefits of MSW resource treatment from 2012 to 2021. The research conclusion is as follows: first, the improvement of MSW treatment efficiency can be enhanced through reasonable policies and measures to promote sustainable urban development and socioeconomic benefits. The input and output levels of MSW treatment in 16 cities all show an upward trend. Second, the 16 MSW treatment systems have good average pure technical efficiency (Chongqing 0.9879, Chengdu 0.9805), average scale efficiency (Nanchong 0.9396), and average comprehensive efficiency (Nanchong 0.9148), but the overall comprehensive efficiency needs improvement. Third, in 2021, Chengdu's ecological and environmental benefits are better than Chongqing's, while Chongqing has a certain degree of input redundancy and output deficiency. Fourth, in the coupling analysis of resource treatment efficiency and environmental improvement benefits in Chengdu and Chongqing between 2012 and 2021, the coordination between resource treatment and environmental improvement in Chengdu lags behind that in Chongqing, but overall, the coupling is improving. Finally, suggestions for improving the efficiency of MSW resource treatment and promoting environmental improvement are presented from the front, middle, and back ends, respectively, to provide a reference for the policy-making of city managers.