In unit root panel tests, one of the important issues is whether or not the cross-sectional units that make up the panel are treated independently. Two types of generation, the first generation tests, are used on the assumption that the cross-sectional units are independent of each other. Also second generation tests that take into account the hypothesis of dependence between sections. For this reason, it is necessary to apply cross-sectional dependence tests before the unit root test. In this study, the independence of the cross-section is tested using Pesaran's (2004) test.
Cross sectional dependence: Pesaran Tests 2004 (CD)
The Peasran (CD) 2004 (cross sectional dependency) test has been developed to check whether variables or residues are correlated between groups in a panel. The test is based on the following statistics:
CD=\(\sqrt{\frac{2T}{N(N-1)}}(\sum _{i=1}^{N-1}\sum _{j=i+1}^{N}{\rho }_{\widehat{ij}})\)
Where N is the number of individuals, T the period and \({\rho }_{\widehat{ij}}\)is the pairwise correlation coefficient of the residues. The null hypothesis for this test assumes that there is no dependence between individuals.
Table 1
Cross-sectional dependence Results Pesaran (2004) CD
Variables
|
CD-test
|
P-value
|
Decision
|
Ln_elec
|
6.882
|
0.000***
|
Dependence
|
Ln_ener
|
1.668
|
0.095*
|
Dependence
|
Ln_mc
|
20.436
|
0.000***
|
Dependence
|
Ln_st
|
17.536
|
0.000***
|
Dependence
|
Ln_tr
|
14.981
|
0.000***
|
Dependence
|
ln_rev
|
41.219
|
0.000***
|
Dependence
|
ln_gdp
|
48.093
|
0.000***
|
Dependence
|
Ln_enerp
|
46.967
|
0.000***
|
Dependence
|
Fdi
|
5.379
|
0.000***
|
Dependence
|
NB: * and *** refers to significance at the 10% and 1% threshold respectively.
From this table, it is clear that the hypothesis of no cross-sectional dependence is rejected at the 1% significance level for all the variables considered, which implies the existence of cross-sectional dependence in the variables across the countries considered. This implies that a shock on one G20 capital market can affect the other G20 capital markets.
Therefore, from the evidence provided by the Pesaran test (2004), we find that the first generation unit root tests are not applicable. So, we apply the second generation Pesaran unit root test (2003), based on the assumption of a cross-sectional dependence, to identify the order of integration of the variables.
Unit root test: Pesaran (2003)
Pesaran (2003) proposed a test to take into account dependencies between individuals. The test is based on the average of the individual t statistics DF (or ADF) of each unit in the panel. He considered an increased DF model in the interindividual dimension or CADF model. This model is written in the absence of autocorrelation of terms:
Table 2
Unit root test results (Pesaran 2003)
|
Level
|
First difference
|
|
Variable
|
Constant and no trend
|
Avec constant et avec trend
|
Avec constant et sans trend
|
Avec constant et avec trend
|
Décision
|
Ln_elec
|
2.864
(0.998)
|
0.623
(0.733)
|
-5.013
(0.000)***
|
-2.079
(0.006)***
|
I(1)
|
Ln_ener
|
1.308
(0.904)
|
0.610
(0.729)
|
-4.014
(0.000)***
|
-2.409
(0.002)***
|
I(1)
|
Ln_mc
|
-0.437
(0.331)
|
0.248
(0.598)
|
-3.681
(0.000)***
|
-1.423
(0.077)*
|
I(1)
|
Ln_st
|
-0.067
(0.437)
|
-0.165
(0.434)
|
-4.289
(0.000)***
|
-2.551
(0.005)***
|
I(1)
|
Ln_tr
|
-0.314
(0.377)
|
-2.580
(0.005)***
|
-7.069
(0.000)***
|
-5.638
(0.000)***
|
I(1)
|
ln_rev
|
-0.568
(0.285)
|
-0.451
(0.326)
|
-3.251
(0.001)***
|
-1.585
(0.057)*
|
I(1)
|
Ln_gdp
|
-2.740
(0.003)***
|
-2.233
(0.013)**
|
-4.511
(0.000)***
|
-1.329
(0.092)*
|
I(0)
|
Ln_enerp
|
-3.101
(0.001)***
|
-2.459
(0.007)***
|
-5.328
(0.000)***
|
-2.325
(0.010)***
|
I(0)
|
Fdi
|
-2.438
(0.007)***
|
-1.795
(0.036)**
|
-7.786
(0.000)***
|
-6.520
(0.000)***
|
I(0)
|
Notes ***, ** and * show significance at the 1%, 5% and 10% levels, respectively |
Table 2 presents the results of the unit root tests which indicate that some variables are stationary in level (ln_gdp, ln_enerp and fdi) and others in first difference (ln_ener, ln_mc, ln_st, ln_tr and ln_rev). Due to the existence of mixed levels of integration between series, we use the ARDL Panel approach rather than the static cointegration test. ARDL panel approach is characterized by a multiplicity of advantages that it highlights and allows to estimate different variables with a different order of stationarity, as in our case in Table 2. We also found that our data suffer from I(0) and I(1). In more, these estimators allow us to estimate short- and long-run relationships and error correction coefficients.
Results of PMG and MG Estimators
In order to identify the impact of the variable of interest, an error correction based on the ARDL model (p,q) with autoregressive distributed lag has been used, focusing on the exclusive property of the PMG model compared to other estimates based on the error correction such as the MG estimator.
Table 3
Estimation Results of Model 1 and 2
|
Model 1:
Electricity consumption Ln_elec
|
Model 2:
Oil consumption
Ln_ener
|
PMG
|
MG
|
PMG
|
MG
|
Long-run coefficients (LR)
|
Ln_mc
|
0.0831
(3.47)***
|
-0.0423
(-0.63)
|
0.1672
(4.80)***
|
0.0962
(2.18)**
|
Ln_rev
|
0.8154
(6.81)***
|
0.9056
(1.86)*
|
0.7597
(6.54)***
|
1.1661
(1.09)
|
Ln_gdp
|
0.1219
(4.03)***
|
-0.0484
(-0.63)
|
-0.0636
(-1.47)
|
-0.2504
(-1.02)
|
Ln_enerp
|
-0.1563
(-6.04)***
|
-0.0707
(-1.54)
|
-0.0947
(-4.45)***
|
-0.0245
(-0.48)
|
Fdi
|
-0.0417
(-4.36)***
|
0.0077
(0.70)
|
0.0095
(1.55)
|
-0.0142
(-0.58)
|
Short-run coefficients (SR)
|
Error-correction coefficient (ec)
|
-0.1362
(-2.61)***
|
-0.9605
(-7.43)***
|
-0.1793
(-4.61)***
|
-0.8630
(-6.13)***
|
Δln_mc
|
0.0021
(0.43)
|
0.0022
(0.12)
|
-0.0059
(-0.95)
|
-0.0392
(-1.45)
|
Δln_rev
|
0.5383
(2.45)**
|
0.1280
(0.34)
|
0.1547
(065)
|
-0.0591
(0.10)
|
Δln_gdp
|
-0.0696
(-1.20)
|
-0.1076
(-0.73)
|
0.0030
(0.04)
|
-0.2634
(-1.20)
|
Δln_enerp
|
0.0354
(2.10)**
|
0.0569
(2.05)**
|
-0.0000
(-0.00)
|
0.0506
(2.07)**
|
Δfdi
|
0.0048
(2.05)**
|
0.0045
(1.20)
|
0.0007
(0.35)
|
0.0034
(0.89)
|
Constante
|
-0.4520
(-2.56)***
|
3.6865
(0.90)
|
0.2743
(4.54)***
|
-2.5311
(-0.43)
|
Tests de Hausman
|
(MG PMG) = 3.41 (0.6371)
|
(MG PMG) = 0.44 (0.9941)
|
Notes: *, ** and *** indicate a significance at 10%, 5% and 1% respectively. The values in brackets represent statistical Zs. For model 1, the offset structure is ARDL (1, 1, 1, 1, 1, 1) and for model 2 is ARDL (1, 1, 1, 0, 1, 1). |
Table 4
Estimation Results of Model 3 and 4
|
Modèle n°3:
Electricity consumption
|
Modèle n°4:
Oil consumption
|
|
PMG
|
MG
|
PMG
|
MG
|
Coefficients de long terme (LR)
|
Ln_st
|
-0.0026
(-0.26)
|
0.0249
(1.03)
|
0.1401
(7.30)***
|
0.1295
(1.26)
|
Ln_rev
|
0.9253
(13.40)***
|
0.2604
(0.75)
|
0.9043 (12.33)***
|
-2.3829
(-0.86)
|
Ln_gdp
|
0.0933
(4.03)***
|
0.0416
(0.59)
|
-0.1019
(-4.66)***
|
0.5992
(0.97)
|
Ln_enerp
|
-0.0989
(-7.32)***
|
-0.0797
(-1.51)
|
-0.0327
(-1.95)*
|
-0.1156
(-1.80)*
|
Fdi
|
0.0056
(1.69)*
|
-0.0008
(-0.09)
|
0.0001
(0.02)
|
0.0145
(0.39)
|
Coefficients de court-terme (SR)
|
Coefficients de correction d’erreur (ec)
|
-1.9184
(-2.29)***
|
-0.7355
(-4.09)***
|
-0.1527
(-3.01)***
|
-0.8031
(-7.73)***
|
Δln_st
|
0.0069
(1.69)*
|
0.0019
(0.17)
|
-0.0010
(-0.14)
|
.0033
(0.28)
|
Δln_rev
|
0.4948
(2.58)***
|
0.3579
(0.88)
|
0.2291
(0.75)
|
-0.0594
(-0.15)
|
Δln_gdp
|
-0.0873
(-1.13)
|
-0.0576
(-0.61)
|
-0.0283
(-0.21)
|
-0.0046
(-0.04)
|
Δln_enerp
|
0.0348
(2.20)**
|
0.0464
(1.97)**
|
-0.0144
(-0.35)
|
0.0305 (1.66)*
|
Δfdi
|
0.0006
(0.46)
|
0.0078
(1.54)
|
0 .0019
(0.93)
|
0.0058 (1.22)
|
Constante
|
-0.6505
(-2.16)**
|
2.8776
(0.78)
|
0.2269 (3.10)***
|
3.8942
(1.57)
|
Tests de Hausman
|
(MG PMG) = 0.59 (0.9884)
|
(MG PMG) = 5.22 ( 0.3896)
|
Notes: *, ** and *** indicate a significance at 10%, 5% and 1% respectively. The values in brackets represent statistical Zs. For model 1, the offset structure is ARDL (1, 0, 0, 1, 1, 1) and for model 2 is ARDL (1, 1, 0, 0, 1, 1). |
Table 5
Estimation Results of Model 5 and 6
|
Modèle n°5:
Electricity consumption
|
Modèle n°6:
Oil consumption
|
PMG
|
MG
|
PMG
|
MG
|
Coefficients de long terme (LR)
|
Ln_tr
|
-0.0067
(-0.59)
|
-0.0889
(-0.93)
|
-0.0208
(-1.02)
|
0.0518 (1.16)
|
Ln_rev
|
1.0133
(16.11)***
|
0.3869 (1.04)
|
0.4264 (3.85)***
|
0.6164
(1.31)
|
Ln_gdp
|
0.0579 (2.93)***
|
0.0634 (1.02)
|
0.0641 (1.39)
|
-0.1889
(-0.97)
|
Ln_enerp
|
-0.0828
(-7.37)***
|
-0.0791
(-1.44)
|
-0.0926
(-5.64)***
|
-0.0378
(-0.89)
|
Fdi
|
0.0063
(1.75)*
|
-0.0240
(-1.17)
|
0.0363 (6.53)***
|
-0.0050
(-0.25)
|
Coefficients de court-terme (SR)
|
Coefficients de correction d’erreur (ec)
|
-0.2309
(-2.70)***
|
-1.1406
(4.95)***
|
-0.1929
(-3.16)***
|
-1.0601
(-4.87)***
|
Δln_tr
|
-0.0024
(-0.35)
|
-0.0241
(-1.24)
|
0.0079 (0.69)
|
− .00118
(-0.42)
|
Δln_rev
|
0.6290 (3.12)***
|
-0.1882
(-0.47)
|
0.3249 (1.24)
|
-0.1459
(-0.28)
|
Δln_gdp
|
-0.0901
(-1.23)
|
0.0420
(0.41)
|
-0.0166
(-0.18)
|
-0.0086
(-0.08)
|
Δln_enerp
|
0.0279 (1.88)*
|
0.0875 (2.98)***
|
-0.0056
(-0.17)
|
0.0745 (2.33)**
|
Δfdi
|
0.0011
(0.86)
|
0.0064
(0.79)
|
-0.0016
(-0.62)
|
0.0042 (0.53)
|
Constante
|
-0.7464
(-2.52)**
|
5.7411 (1.96)**
|
0.3474 (3.00)***
|
8.339
(1.56)
|
Tests de Hausman
|
(MG PMG) = 0.69 (0.9834)
|
(MG PMG) = 0.69 (0.9835)
|
Notes: *, ** and *** indicate a significance at 10%, 5% and 1% respectively. The values in brackets represent statistical Zs. For model 1, the offset structure is ARDL (1, 0, 0, 1, 1, 0) and for model 2 is ARDL (1, 0, 1, 0, 1, 0). |
Tables 3, 4 and 5 presents the estimate of PMG and MG along with the Haussman test to measure efficiency and consistency between them.
Before analyzing the variable coefficients, it is important to mention that the estimated coefficient for the error correction mechanism (ECT) is significant and negative in all cases. The tables (3, 4 and 5) show that the error correction coefficient is negative and significant at a level of 1% for models (1) to (6), which confirms the accuracy of the error. Indeed, there is a statistically significant long-term relationship between dependent and independent variables.
The results of estimation by PMG, as the most efficient estimator compared to the MG estimator, indicate that stock market development indicators have higher values of long-term coefficients than short-term parameters. The findings show that the increase in stock market size measured by market capitalization of listed companies (% of GDP)of 1% increases electricity and oil consumption by 0.083 and 0.167 respectively in the long term (Table 3). However, short-run results show that market capitalization has no effect on energy consumption (electricity and oil).
For indicators measuring stock market liquidity, the results show, in the long term, that the stock traded total value (% of GDP) increases positively and significantly in oil consumption (Table 4). The results show that a 1% increase in the value of the stock traded total value (% of GDP) increases oil consumption by 0.1405. However, for electricity consumption, the stock traded total value has no significant effect.
On the short run, the stock traded total value increases electricity consumption with a slight coefficient. An increase of this indicator by 1% increases electricity consumption by 0.0069.
Table 5 presents the results of the turnover ratio as another indicator that measures stock market liquidity. These results show that the turnover ratio has no significant effect on electricity and oil consumption in either the long or short run. These results are similar to the results of Ulusoy and Demiralay (2017) who found that the turnover ratio does not affect energy consumption in OECD member countries. Contrary to the results of Chang (2015) which find that the turnover ratio has a negative and significant impact on energy consumption in advanced economies while it has a positive and significant impact in emerging and developing countries.
Concerning the control variables, our result show that economic growth (ln_gdp) significantly affects electricity consumption while, overall, it does not significantly affect oil consumption in the long term. However, in the short term, economic growth has no effect on energy consumption (oil and electricity).
The income has a positive and significant statistical effect on electricity consumption in the long and short run. On the other hand, income has a positive and significant impact on oil consumption only in the long run. The results show that electricity demand in G20 countries is much more affected by changes in per capita income than oil demand. As found Ulusoy and Demiralay (2017) for OECD member countries.
Concerning energy price, we have found that it negatively affects electricity consumption in the long term; this is in line with economic theory which suggests that when the price increases, demand decreases. In the short term, the price of energy has a positive impact on electricity consumption. Oil consumption has not been affected by energy prices in either the long or short term.
Many studies have shown significant impacts of per capita income and real price on energy demand estimates (see, for example, Belke et al (2011), Bernstein and Madlener (2015).
Destek (2018), observed that real income is positively correlated with energy consumption and that energy prices have a negative impact on energy consumption.
The results indicate that overall foreign direct investment inflows do not significantly affect energy consumption. Lee (2013) shows that there is no convincing evidence of a link between FDI and the use of clean energy.
Sadorsky (2010) suggests two reasons why stock markets affect energy demand. The first effect, short-run activity, is the wealth (level) effect. As a leading indicator of future economic prospects, the increase in stock market activity affects consumer and business confidence, which in turn increases energy demand. The successful development of the stock market is accompanied by an increase in financial regulations such as accounting and reporting standards. These increases in financial regulation strengthen investor confidence. This increased investor confidence is particularly important to attract foreign investors.
The second theoretical effect is the efficiency effect, the investment canal that helps companies access the source of financing with equity financing. The development of stock markets increases diversification and liquidity, which increases the amount of investment in higher-yield, higher-risk projects. As the development of stock markets increases the amount of funds available for investment projects, it is expected that the development of stock markets will lead to more investment, economic growth and energy demand.
Our empirical results confirm the existence of these two effects. The size of the stock market (market capitalization) has a positive and significant long-term impact on electricity consumption at the 1% level in G20 countries. For electricity consumption, long-term results indicate that the size of the stock market measured by market capitalization and liquidity (total value of traded shares) have a positive and statistically significant impact on oil demand at the 1% threshold. In the short term, the liquidity of the stock markets increases electricity consumption.
The positive effect of the development of stock markets on energy consumption is consistent with some previous work. For example, Hasnaoui (2014) finds a significant effect of stock market developments on OECD countries' energy consumption by conducting a Principal Component Analysis (PCA).
In the case of EU countries, the study by Çoban and Topçu (2013) shows that stock market developments have no significant effect on energy consumption in general, but that they have a significant influence on energy consumption in the old member countries.
The empirical results presented show that the increased development of stock markets increases energy demand in the economies of G20 member countries. Since the development of stock markets in these economies is expected to increase only in the future, this additional increase in energy demand linked to increased financial development should be taken into account when modeling energy demand in G20 countries.