Table 3.

Descriptive statistics of the variables.

Variable	Variable	Unit	Mean	SD	Min	Max
Input	Employed persons	10,000 persons	2703.55	2155.50	279.00	7150.25
	Capital stock	100 million	106786.50	90953.48	10512.23	298851.11
	Total energy consumption	10,000 tce	15200.83	12119.25	1601.00	41826.80
Desired output	GDP	100 million yuan	23589.36	18439.97	1519.23	93014.74
Undesired output	Environmental pollution comprehensive index	–	48883.38	40979.25	6557.08	181211.54
Dependent variable	CTFP	–	1.43	0.467	0.91	5.14
Independent variable	DIG	–	0.37	0.17	0.08	0.98
Control variables	PGDP	RMB	8920.77	13908.29	160.82	127760.7
	POP	Person/ square kilometer	466.50	697.17	7.89	3922.86
	ENVR	%	1.32	0.77	0.22	4.24
	FDI	%	0.02	0.02	0.00	0.08
	ST	%	0.93	0.33	0.06	1.90
Mediator variables	RD	%	1.62	1.07	0.33	6.01
	KL	RMB/person	42.77	17.39	19.16	116.65
	HC	year	9.32	0.89	7.68	12.78

“–” means there is no unit, and the result is calculated by the entropy method.