The relationship between renewable energy consumption, international tourism, trade openness, innovation and carbon dioxide emissions: international evidence

Figures & data

Table 1. Variables, measurement, and data sources.

Variables	Abb.	Variables measurement	Data source
Carbon dioxide emissions	CO2	Carbon dioxide emissions (metric tons per capita)	(WDI, 2022)
Renewable energy consumption	REC	Renewable energy consumption (% of total final energy consumption)	(WDI, 2022)
Urban population growth	UPG	Annual (%)	(WDI, 2022)
Trade openness	TO	${\displaystyle \frac{Exports+imports}{GDP}}$(constant 2015 US$)	(WDI, 2022)
Foreign direct investment	FDI	Foreign direct investment, net inflows (% of GDP)	(WDI, 2022)
International tourism	IT	International tourism, number of arrivals	(WDI, 2022)
Gross domestic product	GDP	GDP per capita (constant 2015 US$)	(WDI, 2022)
Innovation	INNOVA	Patent applications, residents, number of patent applications	(WDI, 2022)

Note: WDI = World Development Indicators.²

Table 2. Description of the variables.

Variables	Mean	Minimum	Maximum	Std. Dev.
CO2	5.220	0.102	20.469	3.989
REC	22.806	0.194	85.628	20.423
UPG	1.472	−2.282	7.925	1.457
TO	0.681	0.007	3.525	0.471
FDI	167.66037446^1	−3.443^1	7.338^1	50416624602^1
IT	18757522.4^1	14000^1	217877000^1	35205147.8^1
GDP	17047.33^1	512.0966^1	88413.19^1	18364.06^1
INNOVA	15696.57	1	387364	56223.31
Observations	1590	1590	1590	1590

¹These values are converted in $US trillion for ease of interpretation.

The data is collected by the World Bank dataset.

Table 5. Correlations between variables.

Variables	CO2	Re	UPG	TO	FDI	IT	GDP	Innovation
CO2	1.000
Re	−0.615	1.000
UPG	−0.354	0.394	1.000
TO	0.004	−0.255	−0.158	1.000
FDI	0.014	−0.036	−0.003	0.051	1.000
IT	0.016	−0.044	−0.090	0.149	0.037	1.000
GDP	0.129	−0.077	0.005	0.100	0.065	0.102	1.000
Innovation	−0.039	−0.064	−0.051	−0.083	0.033	0.085	−0.046	1.000

The data is collected by the World Bank dataset.

Table 3. Test of panel unit root.

Variables	LLC		Im-Pesaran-Shin		Breitung		Fisher (chi-squared)
	Level	First difference	Level	First difference	Level	First difference	Level	First difference
CO2	−0.502	−14.402***	2.664	−20.285***	6.969	−11.230***	210.506***	1280.581***
REC	2.596	−14.206***	7.265	−20.182***	9.051	−16.570***	97.287	1307.350***
UPG	−7.248***	−12.190***	−4.268***	−16.753***	4.394	−7.457***	358.534***	1203.989***
TO	−7.470***	−35.699***	−1.149	−21.416***	7.866	−16.116***	126.390*	1416.183***
FDI	−10.886***	−24.226***	−16.721***	−26.337***	−13.564***	−22.116***	832.693***	2683.397***
IT	−4.356***	−18.213***	−3.698***	−21.567***	1.466	−26.301***	180.900***	1475.262***
GDP	−1.280	−5.066***	5.251	−17.500***	11.578	−11.308***	109.892	1014.003***
INNOV	−3.562***	−18.992***	−8.018***	−23.802***	−2.245**	−16.117***	479.305***	2081.023***

*** Significant at 1%, ** 5% and * 10%.

Table 4. Panel cointegration test results.

Westerlund	Statistics	Probability
Variance ratio (all panels)	2.274	0.011
Kao
Modified-DF	−2.012	0.022
Dickey–Fuller (DF)	−4.969	0.000
Augmented-DF	−1.236	0.108
Unadjusted modified-DF	−1.775	0.037
Unadjusted-DF	−4.844	0.000
Pedroni
Modified variance ratio	−9.264	0.000
Modified Phillips-Perron	5.768	0.000
Phillips-Perron	−1.519	0.000
Augmented Dickey–Fuller	−1.103	0.134

Table 6. Long run estimation of FMOLS and DOLS models.

Variables	FMOLS	DOLS
REC	−0.112*** (0.011)	−0.120*** (0.009)
UPG	−0.491*** (0.161)	−0.341*** (0.053)
TO	−0.001*** (0.000)	−0.001*** (0.000)
FDI	−0.000 (0.000)	−0.000 (0.000)
IT	−0.000 (0.000)	−0.000 (0.000)
GDP	0.0008* (0.0004)	0.0009*** (0.0001)
Innov	−0.001* (0.000)	−0.001*** (0.000)

*** Significant at 1%, and * 10%.

Table 7. Generalised method of moments (GMM)-system estimator.

Variables	OLS	FEM	GMM system
CO2t-1			0.649*** (0.020)
Re	−0.117*** (0.004)	−0.068*** (0.004)	−0.044*** (0.002)
UPG	−0.418*** (0.056)	−0.010 (0.031)	−0.007 (0.008)
TO	−0.001*** (0.000)	−0.0002** (0.000)	−0.0004*** (0.0000)
FDI	−0.000 (0.000)	−0.000* (0.000)	−0.000*** (0.000)
IT	0.000 (0.000)	0.0001** (0.000)	0.000*** (0.000)
GDP	0.0008*** (0.0001)	−0.0002*** (0.000)	0.0003*** (0.000)
INNOV	−0.001*** (0.000)	−0.0001** (0.000)	−0.000*** (0.000)
C	9.740*** (0.297)	7.212*** (0.125)	2.997*** (0.143)
Observations	1590	1590	1537
R^2	0.440	0.198
Adj R^2	0.439
Breusch–Pagan	chi2(1) = 150.74 Prob > F = 0.000
Wooldridge test	F(1,52) = 131.250 Prob > F = 0.000	F(1,52) = 131.250 Prob > F = 0.000
Modified Wald		chi2(53) = 35123.51 Prob > chi = 0.0000
AR(1)			−4.78 (0.000)
AR(2)			−0.69 (0.493)
Hansen test			51.04 (0.160)

 *** Significant at 1%, ** 5% and * 10%.

Table 8. Generalised Method of Moments (GMM)-System Estimator for high-income and middle and low-income countries.

Variables	High income	Middle–Low income
CO2t-1	0.945*** (0.016)	0.924*** (0.031)
Re	−0.013*** (0.004)	−0.000 (0.002)
UPG	0.023* (0.012)	0.118** (0.046)
TO	−0.000*** (0.000)	0.001** (0.000)
FDI	−0.000** (0.000)	−0.001* (0.000)
IT	0.000*** (0.000)	0.001** (0.000)
GDP	0.000 (0.000)	−0.000 (0.000)
INNOV	−0.000***	−0.000* (0.000)
C	0.502*** (0.156)	−0.428*** (0.133)
Observations	1160	377
AR(1)	(−4.60) 0.000	(−1.95) 0.052
AR(2)	(−1.12) 0.263	(1.15) 0.251
Hansen test	(28.26) 0.249	(3.38) 0.336

 *** Significant at 1%, ** 5% and * 10%.