Evaluation of the Effects of the Belt and Road Initiative on the Unified Economic and Environmental Efficiency of Transportation Infrastructure in China Based on Range-Adjusted Measure Model and Difference in Difference Model

Table 6

Regional differences in the effects of the Belt and Road Initiative on the unified economic and environmental efficiency of transportation infrastructure.

Indicator	Eastern region	Central region	Western region
	0.0618 (0.0238)	−0.0344 (0.0238)	−0.0146 (0.0188)
Constant	2.0008 (0.1290)	1.8901 (0.2707)	2.1573 (0.0744)
Control variable	Yes	Yes	Yes
Time fixed effect	Yes	Yes	Yes
Region fixed effect	Yes	Yes	Yes
Observations	132	96	132
	0.5338	0.5133	0.7659

Note: the standard error is shown in parentheses. , , and indicate, respectively, a significance level of 10%, 5%, and 1%.