China 2 Influencing factor Influencing factors 2 Slack-based measures 2 econometrics 2 economic development 2 urbanization Autocorrelation 1 Chinese cities 1 Cities 1 City 1 Eco-efficiency 1 Economic and social effects 1 Economic development 1 Efficiency 1 Emission control 1 Energy efficiency 1 Energy saving and emission reduction efficiency 1 Energy-saving and emission reductions 1 Environmental regulations 1 Indices systems 1 Input-output 1 Input-output index system 1 Reduction efficiency 1 SBM-Undesirable model 1 Slack-based measure considering undesirable-output model 1 Spatial autocorrelation 1 Spatial autocorrelations 1 Spatial econometric 1 Spatial econometric models 1