Table 6.

Explanatory variables.

Variable	Description of variable	Source
Economic development level (EDL)	The natural logarithm of real GDP based on 2006	EDL is a key influencing factor. Taken from Sener and Karakas [59], who thought that there was a positive correlation between EDL and energy efficiency.
Technological progress (TP)	The natural logarithm of the number of patents authorized by provinces	Drawn from Wang and Wang [52], Zhu et al. [53] and Li and Lin [54], who believed that TP could improve the energy efficiency.
Energy price (EP)	The ratio of total energy price to output price	The change of EP will directly affect the cost and profit of energy use and indirectly influence the energy consumption behavior. Considered based on Antonietti and Fontini [58] and Wang et al. [67], who indicated a positive effect of EP on energy efficiency.
Urbanization level (UL)	The proportion of the urban population in the total population	Drawn from Li et al. [26] and Wang et al. [65], who both held that UL would influence energy efficiency, but in different directions.
Industrial structure (IS)	The proportion of secondary industry output value in regional GDP	Taken from Xiong et al. [55], Zhu et al. [56] and Rongdi et al. [68], who demonstrated that IS had a negative impact on energy efficiency.
Energy consumption structure (EC)	The proportion of coal and oil consumption in total EC	Considered based on zhao et al. [13], Yu et al. [31], and Wang et al. [67], who chose EC as one of influencing factors and thought that EC negatively affected energy efficiency.
Government intervention (GI)	The proportion of general financial expenditure in regional GDP	Drawn from Yu et al. [31] and Rongdi et al. [68], who considered that GI was negatively related to energy efficiency.
Openness degree (OD)	The proportion of foreign investment at the end of year in GDP	Taken from Imbruno and Ketterer [62], Montalbano and Nenci [63] and Pan et al. [64], whose research involved FDI, import and export.