How Do Different Types of Environmental Regulations Affect Green Innovation Efficiency?

Table 2

Description of each variable.

Type	Variable names and symbol	Description of variable	Unit
Explained variable	GI-T, GI-1, GI-2	Calculated by the network DEA model	—
Explanatory variable	CER	Number of environmental administrative punishment cases	Case
	MER	Storage amount of sewage charge	10000 yuan
	VER	Number of environmental letters and visits	Case
Independent variables	OPEN	Foreign direct investment	10000 US dollars
	IP	Ratio of the secondary industry’s output value to the GDP	%
	EDU	Number of students enrolled in higher education in per 100,000 people	P
	ECO	GDP per capita	Yuan