Research Article

Impact of Sino-US Trade Liberalization on China’s Carbon Emissions and Future Works on Fractional Phenomenon

Table 4

Robustness test of changing the core explanatory variables.

(1)(2)(3)(4)

First stage regressionExplained variable Lnexport
IV
exchange rate
0.00253 (0.00069)0.00258 (0.00072)0.00277 (0.00068)0.00281 (0.00068)
Other explanatory variables
F value13.4312.7416.4916.84

Second stage regressionExplained variable LnCO2
Lnexport−0.1699 (0.0907)−0.235 (0.092)−0.15 (0.0756)−0.152 (0.075)
Lnpop0.015 (0.018)0.00068 (0.018)0.024 (0.0163)0.0226 (0.0164)
Lnpgdp4.447 (0.606)3.99 (0.709)2.443 (0.595)2.548 (0.59)
(Lnpgdp)2−0.19 (0.0307)−0.161 (0.036)−0.119 (0.035)−0.114 (0.0345)
Es1.23 (0.15)1.071 (0.1385)1.054 (0.139)
Lnsec0.32 (0.101)0.297 (0.102)
Lncar0.23 (0.059)0.214 (0.0595)
Lnrd0.0536 (0.0373)
Cons−15.57 (3.383)−14.97 (3.857)−6.96 (2.78)−17.72 (4.982)
Observations470452451450
Province-fixed effectYesYesYesYes
Year-fixed effectNoNoNoNo
Adjusted R20.95280.95980.96790.9679

, , and represent the significance level of 1%, 5%, and 10%, respectively.