Comparative analysis of asymmetric impact of cashew nuts and cocoa beans exports on Ghana’s economic growth: a non-linear ARDL approach

Figures & data

Table 1. Descriptive statistics of the parameter variables from 1970 to 2019.

	RGDP	CASHEW	COCOA	EXC	FDI	GCF	INF
Mean	23.560	7.350	13.280	−3.250	0.200	2.710	2.980
Median	23.400	6.100	13.060	−2.230	0.510	2.750	2.890
Maximum	24.770	13.800	14.710	1.650	2.250	3.430	4.810
Minimum	22.850	3.400	12.150	−9.190	−3.090	1.320	−0.900
Std. Dev.	0.600	3.120	0.680	3.850	1.520	0.520	0.950
Coef. of Var.	2.550	42.450	5.120	−118.460	7600	19.190	31.880
Skewness	0.620	0.600	0.590	−0.420	−0.490	−0.620	−1.060
Kurtosis	2.050	1.970	2.300	1.660	2.170	2.720	7.170

Note: All variables are log transformed. Coefficient of Variation (CV) is computed as CV = $\mathrm{\sigma }/\overline{X}$*100 where $\mathrm{\sigma }$ is the standard deviation; and $\overline{X}$ is the mean.

Source: Author’s Computation (2021).

Table 2. Pairwise correlation analysis for the NARDL model.

Variables	RGDP	CASHEW	COCOA	EXC	FDI	GCF	INF
RGDP	1
CASHEW	0.953***	1
COCOA	0.876***	0.850***	1
EXC	0.881***	0.832***	0.678**	1
FDI	0.788***	0.729***	0.627***	0.630***	1
GCF	0.707***	0.647***	0.467***	0.765***	0.697***	1
INF	−0.527***	−0.586***	−0.399**	−0.381**	−0.479***	−0.395**	1

Note: All variables are log transformed. *** and ** indicates stationarity at significance levels of 1%, and 5% levels, respectively.

Source: Author’s Computation (2021).

Table 3. Results of DF-GLS and KPSS unit root tests (intercept option).

Variable	DF-GLS test		KPSS test
	(1%: −2.59, 5%: −1.94, 10%: −1.61)		(1%: 0.739, 5%: 0.463, 10%: 0.347)
	Levels	First difference IO	Levels	First difference IO
RGDP	−0.780	−4.410*** I (1)	0.881	0.685*** I (1)
EXC	−0.170	−1.780* I (1)	0.897	0.194*** I (1)
GCF	−1.440	−6.700*** I (1)	0.619***	0.104 I (0)
INF	−2.620***	−5.540 I (0)	0.517***	0.266 I (0)
FDI	−1.500	−4.650*** I (1)	0.602***	0.165 I (0)
CASHEW	−0.740	−8.160*** I (1)	0.837	0.185*** I (1)
COCOA	−0.380	−1.820* I (1)	0.700***	0.091 I (0)

Note: All variables are log transformed. *** and * indicates stationarity at significance levels of 1% and 10% levels, respectively.

Source: Author’s Computation (2021).

Table 4. Results of NARDL bounds cointegration test under an asymmetric framework.

Model		K	F-statistic
RGDP		12	7.670
	LBC I (0)	UBC I (1)
10%	1.830	2.940
5%	2.060	3.240
1%	2.540	3.860

Source: Author’s Computation (2021).

Table 5. Short-run NARDL estimates of the impact of cashew nuts and cocoa beans exports on economic growth.

Variable	Coefficient	Std. Error	Prob.
D(LCASHEW_POS)	0.016***	0.004	0.001
D(LCASHEW_POS(−1))	−0.016***	0.005	0.002
D(LCOCOA_POS)	0.110***	0.020	0.000
D(LCOCOA_NEG)	0.049*	0.026	0.076
D(LEXC_POS)	0.057***	0.016	0.002
D(LEXC_NEG)	−135.166***	10.969	0.000
D(LFDI_NEG)	0.067***	0.012	0.000
D(LFDI_NEG(−1))	−0.089***	0.015	0.000
D(LINF_NEG)	−0.001	0.005	0.883
D(LINF_NEG(−1))	−0.028***	0.006	0.000
ECT(−1)	−0.839***	0.068	0.000

Note: All variables are log transformed. *** and * indicate significance levels of 1% and 10% levels, respectively.

Source: Author’s Computation (2021).

Table 6. Long-run NARDL estimates of the impact of cashew nuts and cocoa beans exports on economic growth.

Variable	Coefficient	Std. error	Prob.
LCASHEW_POS	0.051***	0.012	0.000
LCASHEW_NEG	0.002	0.011	0.863
LCOCOA_POS	0.203***	0.033	0.000
LCOCOA_NEG	0.183***	0.054	0.003
LEXC_POS	0.163***	0.035	0.000
LEXC_NEG	−146.123***	38.876	0.001
LGCF_POS	0.105*	0.053	0.060
LGCF_NEG	−0.079*	0.042	0.073
LFDI_POS	0.003	0.010	0.772
LFDI_NEG	0.260***	0.030	0.000
LINF_POS	−0.017	0.018	0.375
LINF_NEG	0.005	0.028	0.870

Note: All variables are log transformed. ***^, **, and * indicate significance levels of 1, 5, and 10% levels, respectively.

Source: Author’s Computation (2021).

Table 7. Results of Granger causality test.

Null hypothesis	F-statistic	Prob.	Results
LCASHEW → LRGDP	0.482	0.621	Unidirectional
LRGDP → LCASHEW	6.433	0.004
LCOCOA → LRGDP	0.743	0.482	Unidirectional
LRGDP → LCOCOA	3.296	0.047

Source: Author’s Computation (2021).

Data availability statement

Data will be made available upon reasonable request.