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 2

Descriptive statistics of the variables.

Variables	Count	Mean	Std. Dev	Min	Median	Max
Lnee	270	3.169	0.724	1.280	3.114	4.884
Productivity	270	27.170	10.345	10.378	26.763	90.304
Machinery	270	6.360	3.060	2.100	5.800	27.400
Urbanratio	270	0.547	0.131	0.291	0.526	0.896
Lnesratio	270	−1.754	0.624	−3.604	−1.676	1.000
Rdratio	270	0.015	0.011	0.002	0.012	0.061
Lneninratio	270	−3.561	0.338	−4.639	−3.571	−2.821
Pgdp	270	4.270	2.259	0.882	3.731	11.820