| Literature DB >> 34258464 |
Francis Atsu1, Samuel Adams2, Joseph Adjei3.
Abstract
The ICT, energy consumption, and carbon dioxide emissions (CO2) relationship is examined for South Africa spanning the period 1970-2019, while controlling for the effects of financial development. The findings of the study based on the Autoregressive Distributed Lag (ARDL), Dynamic Ordinary Least Squares (DOLS), and Fully Modified Ordinary Least Squares (FMOLS) estimators show that ICT and fossil fuel consumption contribute to carbon dioxide emissions, while renewable energy consumption and financial development reduce carbon dioxide emissions. Specifically, the results show that a 1% increase in ICT activities will increase CO2 emissions by 0.565% in the long-term, and any temporary shock to this long-run relationship is corrected by 93.20%. Further, there is no evidence of threshold effect of ICT on carbon emissions.Entities:
Keywords: ARDL; Carbon dioxide emissions; Financial development; Fossil fuel; ICT; Renewable energy
Year: 2021 PMID: 34258464 PMCID: PMC8258858 DOI: 10.1016/j.heliyon.2021.e07328
Source DB: PubMed Journal: Heliyon ISSN: 2405-8440
Figure 1Emissions 1960–2016.
Variable definition and sources.
| No | Variable | Definition | Sources |
|---|---|---|---|
| 1 | CO2 emissions (metric tons per capita) | WDI | |
| 2 | Fixed telephone subscription | WDI | |
| 3 | Broad money (% of GDP) | WDI | |
| 4 | Domestic credit provided by financial sector (% of GDP) | WDI | |
| 5 | Domestic credit to private sector (% of GDP) | WDI | |
| 6 | Domestic credit to private sector by banks (% of GDP) | WDI | |
| 7 | Foreign direct investment, net inflows (% of GDP) | WDI | |
| 6 | Gross domestic product (GDP per capita) | WDI | |
| 7 | Trade (sum of exports and imports) (% of GDP) | WDI |
Notes: The term WDI represents the World Bank's world development indicators database.
Descriptive statistics and correlation.
| Panel A: Descriptive Statistics | |||||||
|---|---|---|---|---|---|---|---|
| Statistic | |||||||
| Mean | 8.593 | 7.908 | 17.278 | 87.364 | 86.676 | 52.791 | 3681.103 |
| Median | 8.598 | 8.301 | 17.094 | 87.135 | 84.475 | 52.730 | 3146.993 |
| Max. | 9.979 | 12.388 | 19.121 | 90.506 | 127.541 | 72.865 | 8007.413 |
| Mini. | 6.786 | 3.458 | 15.570 | 84.243 | 53.358 | 37.487 | 834.553 |
| Std. Dev. | 0.838 | 2.354 | 0.817 | 1.664 | 23.899 | 7.674 | 1946.299 |
| Skewness | -0.126 | -0.213 | 0.176 | 0.013 | 0.240 | 0.046 | 0.523 |
| Kurtosis | 2.211 | 1.895 | 2.307 | 2.009 | 1.456 | 2.667 | 2.181 |
| JB | 1.431 | 2.923 | 1.259 | 2.047 | 5.447 | 0.249 | 3.673 |
| Prob. | 0.489 | 0.232 | 0.533 | 0.359 | 0.066 | 0.883 | 0.159 |
| Obs. | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| 1.000 | |||||||
| 0.467 | 1.000 | ||||||
| -0.669 | -0.088 | 1.000 | |||||
| -0.109 | -0.746 | -0.142 | 1.000 | ||||
| 0.310 | 0.602 | -0.316 | -0.508 | 1.000 | |||
| 0.141 | -0.093 | -0.415 | 0.122 | 0.498 | 1.000 | ||
| 0.450 | 0.400 | -0.518 | -0.370 | 0.821 | 0.519 | 1.000 | |
Notes: The term fin is the composite index of financial development obtained from the individual measures of financial development (dcps, dcbs, dcfs, and bmoney) using Cronbach's Alpha method as presented in Table 3.
Item-analysis of financial development measures.
| Item | Obs | Sign | Item-test | Item-rest | alpha |
|---|---|---|---|---|---|
| 48 | + | 0.995 | 0.984 | 0.705 | |
| 48 | + | 0.992 | 0.980 | 0.662 | |
| 49 | + | 0.939 | 0.926 | 0.849 | |
| 50 | + | 0.720 | 0.657 | 0.882 | |
| Test scale (fin) | 0.852 |
Notes: Using the STATA “alpha”, we compute the Cronbach's Alpha where, per literature, values within the range 0.7 and above are more appropriate.
Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) unit root tests.
| Variable | ADF-Test | PP-test | Outcome | ||
|---|---|---|---|---|---|
| Const | Const + Trend | Const | Const + Trend | ||
| lnco2 | -2.655∗ | -2.314 | -2.711∗ | -2.435 | Non-stationary |
| lnfts | 0.074 | -2.244 | -0.563 | -1.056 | Non-stationary |
| lnren | -2.867∗ | -2.903 | -2.570 | -2.766 | Non-stationary |
| lnfoss | -1.631 | -1.684 | -1.616 | -1.748 | Non-stationary |
| lntrade | -1.894 | -2.083 | -1.844 | -2.061 | Non-stationary |
| lnfin | -1.440 | -1.332 | -1.440 | -1.044 | Non-stationary |
| lngdp | -2.345 | -3.220∗ | -2.090 | -2.651 | Non-stationary |
| lnco2 | -7.255∗∗∗ | -7.264∗∗∗ | -7.234∗∗∗ | -7.246∗∗∗ | I(1) |
| lnfts | -7.526∗∗∗ | -7.670∗∗∗ | -5728∗∗∗ | -6.029∗∗∗ | I (1) |
| lnren | -4.884∗∗∗ | -4.828∗∗∗ | -6.911∗∗∗ | -6.838∗∗∗ | I (1) |
| lnfoss | -7.854∗∗∗ | -7.822∗∗∗ | -7.796∗∗∗ | -7.781∗∗∗ | I (1) |
| lntrade | -6.350∗∗∗ | -6.280∗∗∗ | -6.551∗∗∗ | -6.458∗∗∗ | I (1) |
| lnfin | -6.988∗∗∗ | -6.968∗∗∗ | -6.988∗∗∗ | -6.968∗∗∗ | I (1) |
| lngdp | -5.380∗∗∗ | -5.603∗∗∗ | -4.763∗∗∗ | -4.757∗∗∗ | I (1) |
Zivot Andrews Unit root test.
| Variable | Levels | First Difference | Outcome | ||||
|---|---|---|---|---|---|---|---|
| Intercept | Intercept + trend | Intercept | Intercept + trend | ||||
| t-Stat. | Break date | t-Stat. | Break date | t-Stat. | t-Stat. | ||
| -3.378 | 1979 | -3.402 | 1992 | -7.707∗∗∗ | -7.901∗∗∗ | I(1) | |
| 2.449 | 2012 | -0.807 | 1998 | -3.276∗∗ | -4.087∗∗∗ | I(1) | |
| -3.685∗∗ | 1991 | -3.839∗∗ | 1991 | -5.437∗∗∗ | -5.658∗∗∗ | I(1) | |
| -3.881∗∗∗ | 2003 | -3.702∗∗ | 1998 | I(0) | |||
| -2.929 | 1992 | -2.554 | 2011 | -8.171∗∗∗ | -8.527∗∗ | I(1) | |
| -3.412 | 1982 | -3.432 | 1989 | -6.539∗∗∗ | -6.754∗∗∗ | I(1) | |
| -3.551 | 1998 | -3.956 | 2010 | -5.520∗∗∗ | -5.990∗∗∗ | I(1) | |
Notes: Intercept denotes unit root with a structural break in the intercept only, while Intercept + trend denotes root unit with a structural break in the intercept and trend. ∗∗∗/∗∗/∗ represent significance at 1%/5%/10%, respectively.
Results for Narayan and Popp (2010, 2013) unit root test with two structural breaks.
| Panel A: Levels | ||||||
|---|---|---|---|---|---|---|
| Variable | Break in intercept only | Break in intercept and slope | ||||
| t-Stat. | TB1 | TB2 | t-Stat. | TB1 | TB2 | |
| -2.231 | 2002 | 2004 | -3.327∗∗ | 1989 | 2003 | |
| 0.903 | 1986 | 1999 | 1.496 | 1996 | 1999 | |
| -2.270 | 1998 | 2009 | -2.796 | 1990 | 2009 | |
| -1.647 | 1988 | 1992 | -4.242∗∗∗ | 1987 | 2003 | |
| -0.454 | 1991 | 2001 | -0.693 | 1991 | 2001 | |
| -2.006 | 2002 | 2008 | -1.351 | 1982 | 2008 | |
| -3.006 | 1979 | 2002 | -3.027∗ | 1979 | 2002 | |
Notes: TB1 and TB2 represent the two break dates. ∗∗∗/∗∗/∗ significant at 1%, 5% and 10%, respectively.
Long-run relationship and Estimates of ARDL specification.
| Panel A: Test for Long-run relationship | ||||
|---|---|---|---|---|
| Model 1- Bounds F-test | ||||
| ARDL specification | F-statistic | SL | I(0) | I(1) |
| ARDL (1,1,1) | 5.488∗∗∗ | 10% | 2.370 | 3.200 |
| 5% | 2.790 | 3.670 | ||
| 1% | 3.650 | 4.660 | ||
| Ramsey RESET | 1.616 | 0.115 | ||
| Breusch-Godfrey Serial Correlation LM | 0.151 | 0.860 | ||
| Heteroskedasticity Breusch-Pagan-Godfrey | 0.609 | 0.745 | ||
| ARCH Heteroskedasticity | 0.169 | 0.683 | ||
Notes: The optimal lag lengths are determined by SBIC and Δ is the difference operator. The standard errors are in the parenthesis, and ∗∗∗/∗∗/∗ denote 1%,5% and 10% significance, respectively. The term ect denotes the error correction term.
Long-run relationship and estimates of ARDL specification.
| Panel A: Test for Long-run relationship | ||||
|---|---|---|---|---|
| Model 1- Bounds F-test | ||||
| ARDL specification | F-statistic | SL | I(0) | I(1) |
| ARDL (1, 4, 3, 3, 1, 4, 4) | 4.242∗∗∗ | 10% | 1.990 | 2.940 |
| 5% | 2.270 | 3.280 | ||
| 1% | 2.880 | 3.990 | ||
| Ramsey RESET | 0.533 | 0.602 | ||
| Breusch-Godfrey Serial Correlation LM | 12.804 | 0.010 | ||
| Heteroskedasticity Breusch-Pagan-Godfrey | 0.680 | 0.814 | ||
| ARCH Heteroskedasticity | 0.035 | 0.853 | ||
Notes: The optimal lag lengths are determined by SBIC and Δ is the difference operator. The standard errors are in the parenthesis, and ∗∗∗/∗∗/∗ denote 1%,5% and 10% significance, respectively. The term ect denotes the error correction term.
Figure 2Cumulative Sum of Recursive Residuals (CUSUM) Plot. Notes: Lines depict critical bounds at 5% level of significance.
Figure 3Cumulative Sum of square of Recursive Residuals (CUSUMSQ) Plot. Notes: Lines depict critical bounds at 5% level of significance.
Fully-modified OLS and Dynamic OLS regression estimates.
| Variable | Model 1 | Model 2 | ||||
|---|---|---|---|---|---|---|
| Coef. | Std. Error | Prob. | Coef. | Std. Error | Prob. | |
| lnfts | 0.194∗∗∗ | 0.043 | 0.000 | 0.185∗∗∗ | 0.025 | 0.000 |
| lnfoss | 1.448∗ | 0.732 | 0.054 | 1.240∗∗∗ | 0.402 | 0.004 |
| lnren | -1.160∗∗ | 0.214 | 0.000 | -0.964∗∗∗ | 0.144 | 0.000 |
| lnfin | -0.136∗∗∗ | 0.034 | 0.000 | |||
| lntrade | -0.025 | 0.046 | 0.592 | |||
| lngdp | 0.070∗∗∗ | 0.016 | 0.000 | |||
| Constant | -1.411 | 3.599 | 0.697 | -0.883 | 2.080 | 0.674 |
| lnfts | 0.402∗∗∗ | 0.059 | 0.000 | 0.338∗∗∗ | 0.051 | 0.000 |
| lnfoss | 4.514∗∗∗ | 0.987 | 0.000 | 2.792∗∗∗ | 0.705 | 0.000 |
| lnren | -0.671∗∗ | 0.260 | 0.015 | -0.862∗∗∗ | 0.189 | 0.000 |
| lnfin | -0.108∗∗ | 0.048 | 0.028 | |||
| lntrade | 0.011 | 0.064 | 0.863 | |||
| lngdp | 0.021 | 0.025 | 0.394 | |||
| Constant | -16.947 | 5.111 | 0.002 | -8.304 | 3.488 | 0.022 |
Notes: We employed Kao (Engle-Granger based) and Fisher (Combined Johansen) panel cointegration technique to examine the cointegration relationship among the variables under study. The standard errors are in the parenthesis, and ∗∗∗/∗∗/∗ denote 1%,5% and 10% significance, respectively.