Evaluating the Effect of China’s Carbon Emission Trading Policy on Energy Efficiency of the Construction Industry Based on a Difference-in-Differences Method

Table 5

Balance test for PSM.

Variable	Unmatched; Matched	Mean		%Reduct		t-test
		Treated	Control	%Bias	|bias|	t	p > t
Productivity	U	36.775	24.769	105.7		8.6	0
	M	28.553	27.423	9.9	90.6	0.36	0.72
Machinery	U	6.5019	6.325	5.8		0.38	0.705
	M	5.805	5.6612	4.7	18.7	0.16	0.877
Urbanratio	U	0.72339	0.5033	188.9		14.84	0
	M	0.58937	0.59442	−4.3	97.7	−0.19	0.848
Lnesratio	U	−1.8552	−1.7292	−20.3		−1.33	0.185
	M	−1.8887	−1.8012	−14.1	30.6	−0.54	0.594
Rdratio	U	0.02823	0.01152	146.8		13.13	0
	M	0.0165	0.01601	4.3	97.1	0.3	0.762
Pgdp	U	6.6224	3.6821	128.3		10.01	0
	M	4.3698	4.3081	2.7	97.9	0.1	0.92