The Impacts of Freight Trade on Carbon Emission Efficiency: Evidence from the Countries along the “Belt and Road”

Table 6

Heterogeneity test results.

Variable	LCTCEI	LITCEI	LGTCEI	LBPR	LTGR
	(1b)	(2b)	(3b)	(4b)	(5b)
Low fossil energy consumption
LIFT	0.0776	0.0490	0.0295	0.0032	–0.0150
	(0.0097)	(0.0076)	(0.0066)	(0.0052)	(0.0040)
Constant	0.3905	0.2686	0.3319	0.5597	0.7790
	(0.1713)	(0.1341)	(0.1172)	(0.0925)	(0.0713)
Control	Yes	Yes	Yes	Yes	Yes
Section	Yes	Yes	Yes	Yes	Yes
Year	Yes	Yes	Yes	Yes	Yes
N	400	400	400	400	400
R^2	0.347	0.6249	0.5752	0.7603	0.4351
High fossil energy consumption	(1c)	(2c)	(3c)	(4c)	(5c)
LIFT	0.0548	0.0473	0.0535	0.0145	0.0019
	(0.0112)	(0.0099)	(0.0073)	(0.0108)	(0.0074)
Constant	0.6156	2.2646	1.2025	2.2722	–0.1158
	(0.2386)	(0.2100)	(0.1552)	(0.2305)	(0.1571)
Control	Yes	Yes	Yes	Yes	Yes
Section	Yes	Yes	Yes	Yes	Yes
Year	Yes	Yes	Yes	Yes	Yes
N	400	400	400	400	400
R^2	0.4646	0.7091	0.7943	0.6305	0.7989

The parenthesis are the robust standard error values: , , and .