Analysis of the Strategic Emission-Based Energy Policies of Developing and Developed Economies with Twin Prediction Model

Table 2

Unit root test and ARIMA results for methane emission.

Groups	ADF	Possible forms of ARIMA	Regression coefficients (prob)	Ṝ^2	AIC	SIC
26 OECD	−5.83 (0.00)	(2, 1, 2)	AR(2) = −0.67 (0.00) MA(2) = 0.71(0.05)	0.14	21.79	21.83
		(4, 1, 4)	AR(4) = 0.50 (0.00) MA(4) = −0.91(0.02)	0.27	21.5	21.65
		(11, 1, 11)	AR(11) = −0.17(0.23) MA(11) = 0.87 (0.05)	0.62	20.6	20.75
Upper middle income	−4.11(0.00)	(3, 1, 4)	AR(3) = 0.39 (0.02) MA(4) = −0.24 (0.22)	0.07	25.05	25.19
		(11, 1, 11)	AR(11) = −0.8(0.01) MA(11) = −0.94 (0.00)	0.91	22.84	22.99
Middle income	−8.15(0.00)	(1, 1, 6)	AR(1) = −0.18 (0.35) MA(6) = −0.16 (0.42)	0.001	27.33	27.47
		(6, 1, 6)	AR(6) = −0.57 (0.00) MA(6) = 0.96(0.00)	0.38	26.96	27.11
		(15, 1, 15)	AR(15) = 0.01 (0.48) MA(15) = −0.99 (0.02)	0.99	7.64	7.78
Lower middle income	−8.5(0.00)	(1, 1, 4)	AR(1) = −0.38 (0.00) MA(4) = −0.08 (0.24)	0.12	27.31	27.45
		(4, 1, 4)	AR(4) = 0.6 (0.02) MA(4) = −0.94(0.01)	0.15	27.30	27.42
		(15, 1, 4)	AR(15) = 0.15 (0.16) MA(4) = −0.94 (0.01)	0.77	26.48	26.49
Low income	−7.37 (0.00)	(1, 1, 1)	AR(1) = 0.45 (0.00) MA(1) = −0.99 (0.01)	0.24	24.68	24.82
		(1, 1, 4)	AR(1) = −0.31 (0.28) MA(4) = −0.17 (0.21)	0.05	24.89	25.03

Note. Bold marks indicate significant results and the accepted ARIMA structures for which forecasting is made. Source: computed by the authors.