Could the Construction of Sustainable Development Pilot Zones Improve the Urban Environment Efficiency in China?

Table 3

The assessment based on PSM-DID method.

	Difference between experimental group and control group before the implementation of policy	Difference between experimental group and control group after the implementation of policy	DID results
Difference	−0.225	0.092	0.317
Standard error	0.070	0.079	0.105
T value	−3.23	1.17	3.02
value	0.001	0.241	0.003

Note: represents a significance level of 1%.