Table 7.

Panel unit root test results

	CIPS		CADF
	Level	1st diff	Level	1st diff
lnEP	− 1.449	− 2.716***	2.39	− 2.816***
lnENVTAX	0.53	− 5.456***	0.58	− 2.92***
lnREN	− 1.207	− 3.319***	1.136	− 4.256***
lnACT	− 1.063	− 2.349***	1.279	− 3.588***
lnPOP	0.51	− 3.258***	1.207	− 4.256***
lnUR	− 1.562	− 3.558***	− 2.279	− 5.824***

^***, **, and * denote the significance at 1%, 5%, and 10% level, respectively