Impact of Low-Carbon City Policy on Enterprise Investment Efficiency: Based on the Heterogeneity of Chinese Urban Culture

Table 3

Regression results of robustness tests.

Variables	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
	Nonrandom selection of samples	Placebo test	Placebo test	Abnormal value removal	Controlling level of economic development	New energy demonstration city	Environmental criticism	Removal of provinces without pilot cities
LCC	-0.005			-0.005	-0.005	-0.007	-0.005	-0.006
	(-2.32)			(-2.36)	(-2.30)	(-2.80)	(-2.31)	(-2.40)
Before_3		-0.020	-0.004
		(-1.17)	(-1.55)
PGDP					0.000
					(0.59)
Ncity						0.002
						(0.60)
HBYT							-0.007
							(-1.75)
Constant	0.027	0.168	-0.001	0.016	0.024	0.041	0.026	0.010
	(0.66)	(1.88)	(-0.02)	(0.43)	(0.58)	(1.02)	(0.64)	(0.22)
Observations	10,951	3,900	7,051	10,951	10,894	9,724	10,951	9,840
-squared	0.024	0.054	0.034	0.023	0.024	0.020	0.024	0.023
	Yes
Control variables	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Time fixed effects	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Enterprise fixed effects	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Province fixed effects	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Industry fixed effects	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes

Note: robust -statistics are in parentheses; , , and .