Does Digital Economy Contribute to Regional Carbon Productivity? Evidence of China

Table 4

Cointegration test: Kao test results.

Inspection methods		Statistic	p-value
Pedroni	Modified Phillips–Perron t	10.440	0.000
	Phillips–Perron t	−35.972	0.000
	Augmented Dickey–Fuller t	−24.054	0.000
Kao	Modified Dickey–Fuller t	3.617	0.000
	Dickey–Fuller t	4.304	0.000
	Augmented Dickey–Fuller t	1.599	0.055
	Unadjusted modified dickey	3.047	0.001
	Unadjusted Dickey–Fuller t	3.433	0.000
Westerlund	Variance ratio	7.599	0.000

Note., , and indicate the significance at the level of 0.01, 0.05, and 0.1, respectively.