Co-integration and causality between GDP, employment and energy consumption: Empirical evidence on the WAEMU countries

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1 Issues n Busness Managemen and Economcs Vol.2 (11), pp , ovember 214 Avalable onlne a hp:// hp://dx.do.org/ /ibme Journal Issues ISS X Orgnal Research Arcle Co-negraon and causaly beween GDP, employmen and energy consumpon: Emprcal evdence on he WAEMU counres Acceped 11h ovember, 214 Boukary Ouédraogo 1 * and Mamoudou Hassane 2 1CEDRES, Unversé Ouaga 2, Burkna Faso. 2Deparmen of Economcs, Unversy Abdou Moumoun of amey, ger. *Correspondng Auhor E-mal: boukary.ouedraogo@unv-ouaga.bf Tel.: Ths arcle uses daa from he Wes Afrcan Economc and Moneary Unons (WAEMU) zone for he perod o examne he causal relaonshps beween GDP per employee and energy consumpon on one hand, and he relaonshp beween employmen and energy on he oher hand. The mporance of energy consumpon n he WAEMU zone s derved from he nadequacy of energecal resources compared wh needs of economc acves. Therefore, for he robusness of he emprcal resuls, we used Phllps-Perron ess o deermne he level of negraon of varables. The resuls drawn from hese ess led o he concluson ha he seres are saonary wh he excepon of GDP per employmen whch s negraed n order 1. The Hsao s Granger causaly mehod show he exsence of a one-way relaonshp beween GDP per employee on one hand, and beween energy consumpon and he varables employmen and consumpon of energy on he oher hand. Ths s a good reference for polcy makers o well defne he energy sraeges of he WAEMU zone. JEL Classfcaon: C13, C5, C52, E23, E24, Q41, Key words: Energy, GDP, Employmen, Causaly, Co-negraon, WAEMU ITRODUCTIO Energy use n developng counres s ncreasng rapdly. The facors leadng o hs rapd ncrease of energy use nclude populaon growh, economc growh, and urbanzaon. Generally, energy ncludng elecrcy s denfed as he one playng a sgnfcan role n economc developmen, no only because ncreases he producvy of capal, labor and oher facors of producon, bu also because s greaer consumpon, parcularly commercal energy s synonymous wh hgh economc saus of a counry. Many sudes have shown ha energy consumpon s correlaed wh economc growh hence, for example, counres wh a hgher per capa GDP were found o have hgh energy consumpon per capa (Burney, 1995; Anderson 1973; Samolds and Mrolopulos, 1984; Gowen, 1987). Does economc developmen drve o a greaer energy consumpon?or s energy self a smulus for economc developmen? These quesons have led and movaed curosy and neres amongs economss and polcy analyss over he pas decade o sudy he drecon of causaly beween energy consumpon and economc varables such as GDP, ncome, employmen or energy prces (an and Murray, 199; Glaze and Lee, 1997; Cheng and La, 1997; Mash and Mash, 1997; Asafu-Adaye, 2; Yang, 2).Ths s because he drecon of causaly has sgnfcan polcy mplcaons. For example, he concluson of a undreconal causaly runnng from energy consumpon o GDP means an energy dependen economy such ha energy s a smulus for he growh of GDP whch mples ha he lack of energy may negavely affec economc growh or may cause poor economc performance. However, connued causaly runnng from

2 Issues Bus. Manag. Econ. 194 GDP o energy consumpon means a less energy dependen economy such as energy conservaon polces (elecrcy raonng) can be mplemened wh lle or no deleerous effec on he level of economc acvy (GDP). If here s no causaly beween energy consumpon and GDP known as he assumpons of neuraly (Yu and Cho,1985), mples ha energy consumpon s no correlaed wh GDP and as such, polces for energy conservaon can be pursued whou compromsng he economy. However, he drecon of causaly beween energy consumpon and economc varables remans emprcally elusve and conroversal across me, counres and mehodologes. For example, usng he Hsao Granger causaly, Cheng and La (1997) repored a connuous causaly runnng from GDP o energy consumpon n Tawan usng daa from 1954 o Yang (2) used daa from 1954 o 1997 and Granger-causaly echnques for he same counry (Tawan) and obaned a b- dreconal causaly beween energy consumpon and GDP. Glazure and Lee s work (1997) n Souh Korea and Sngapore used error correcon models and co-negraon and repored a b-dreconal causaly beween GDP and energy consumpon n he counres suded. However, connuous causaly runnng from energy consumpon o GDP and no causaly were repored respecvely for Sngapore and Souh Korea when he sandard mehod of Granger -causaly was used. Mash and Mash (1997) repored ha real ncome, energy consumpon and energy prces were only neracve n he causal chan n Korea and Tawan usng error correcon and co- negraon mehods. Asafu-Adaye s work (2) on he causaly beween energy consumpon, energy prces and ncome n Inda, Indonesa, Thaland and he Phlppnes used co-negraon and elecronc counermeasuremen echnques ha produced conroversal resuls. A b-dreconal Granger-causaly beween energy consumpon and ncome was repored for he Phlppnes and Thaland, and a Granger s connued causaly workng from energy consumpon o ncome was repored for Inda and Indonesa. Oher researchers (Jumbe, 24) n Malaw who used sandard echnques of model error correcon and Granger-causaly found a b-dreconal causaly beween elecrcy consumpon (kwh) and GDP, bu a connued causaly workng from non-agrculural GDP o KWH. However, was repored ha energy prces, energy consumpon and ncome are muually correlaed n Thaland and he Phlppnes. Despe varaons n emprcal resuls, hese sudes demonsrae he exsence of a causaly relaonshp beween energy consumpon and economc varables. Excep sudes on supply and demand for energy companes n Sub-Saharan Afrcan (SSA) counres, here s generally lle emprcal research publshed on causaly beween energy consumpon and economc varables repored for SSA counres (Munasnghe, 198; Abdel- Khalek, 1988). The frs conrbuon on he causaly beween energy consumpon and economc varables for hese Afrcan counres was carred ou by Jumbe (24) n Malaw. Kane (29) uses he vecor error correcon model (ECM) and daa from heerogeneous non-saonary panel o nvesgae he relaonshp beween energy demand and economc growh n he WAEMU regon n order o deermne he explanaory varables of energy nensy n gross domesc produc. Anoher sudy analyzed he meanng of causaly beween economc growh and energy consumpon, bu also he naure of he relaonshp beween energy sources for a panel of four WAEMU counres: Benn, Coe d' Ivore, Senegal and Togo over he perod of 197 o 25 (Okey, 21). Oher sudes have also been carred ou ndvdually on some WAEMU and Sub-Saharan Afrcan counres (Ivory Coas, Mal and Congo) o undersand he causaly beween economc growh and energy consumpon (Tmé, 21) consumpon growh (Sacko, 24; Ambapour and Massamba, 25; Tmé, 21). These sudes have argeed some specfc sources of energy such as elecrcy, peroleum producs and have used panel daa for esmaes. The specfcy of hs sudy compared o hose already made on WAEMU les on he use of aggregaed daa (ncludng all sources of energy expressed n ons of ol equvalen) n all WAEMU counres. The obecve of hs sudy s o examne he conegraon and he meanng of causaly beween energy consumpon, employmen and GDP by usng he echnques of error correcon and co-negraon on daa n WAEMU counres. Ths s manly o show ha he ncreased level of acvy (GDP) and herefore he fgh agans unemploymen n hs area s closely lnked o energy consumpon. The focus s specfcally: 1. To check he exsence of a relaonshp beween energy consumpon and economc growh; 2. To deermne he drecon of causaly beween hese varables n order o make suggesons on how energy ssues could be addressed n he fuure n he WAEMU zone. 3. To provde opmal economc and energy polces for member counres of he WAEMU zone. These research obecves answer he followng research queson: Is here a long-erm relaonshp beween energy consumpon and ncreasng level of economc acvy n he WAEMU zone? Whch naurally leads us o he hypohess: here s a susanable lnk beween energy consumpon and economc growh n he WAEMU zone. MODEL AALYSIS AD THE METHODOLOGY Here we adop he Granger causaly es for s smplcy and s suably crera for small samples n appled economcs. Indeed, he works repored by Gulkey Salem

3 Ouédraogo and Hassane 195 (1982) and Geweke e al. (1983) showed ha he applcaon of he Mone Carlo mehod advocaes he Granger causaly es among alernave echnques. Thus, he Granger causaly es poses ha a varable causes o Granger f he predcon of he curren value s enhanced by he use of lagged values. The model In modelng he funcon of energy consumpon and economc growh varable (or he fgh agans unemploymen) n prevous sudes, all varables consdered were expressed n naural logarhm. Therefore, he equaon lnkng economc growh (or unemploymen) and he energy consumpon s specfed as auoregressve model. Consderng Y as GDP per employee (GDPE) and x s he varable energy consumpon (EC) hus: log y = f (logx) s auoregressve general form becomes: p log y log y e1 (1 log x log x e (2) 2 where L s he delay operaor, L= d-1 s he dfference operaor wh he frs dfference gven by: ( 1 y y y 1 By specfyng he equaon: y x z 1 (3) z s he saonary resdue of he co-negraon equaon The deermnaon of causaly Here we adop he Granger causaly mehod n s developed verson accordng o Hsao (1981).Ths mehod s bul around a wo-sep procedure o deermne he opmum number of crossword lag erms and own lags and he drecon of causaly beween wo or more lags by usng he creron of predcon error or fnal error predcon (FPE or fnal error predcon) accordng o Akake (1969). Resumng a runcaed verson of Equaon (1) n he manner of auoregressve models, we oban: y y e1 1 ( 1 (4) Consderng y nally as a one-dmensonal auoregressve process, and akng as he maxmum lag lengh of he conrolled varable y. Accordng o he Hsao procedure, he frs sep s o regress y on y o ake he sum of squared errors (SSE) wh = 1, 2,...,, and hen calculae he FPE. The laer (FPE) s he delay seen n he followng equaon: T n 1 SSE FPE( n) (5) T n 1 T Wh T denoes he oal number of observaons, n s he order of he delay varyng from 1 o, and SSE s he sum of squared errors. Thus, f = 1 [Equaon (4)], here are 1 FPES. The order of delay mus hen be chosen n order o oban he smalles FPE denoed hus: FPE(n*). The followng equaon wll be he second sep accordng o he Hsao procedure: M y y (1 x e2 1 1 ( 1 (6) Where y s consdered as he conrol varable wh a delay of order fxed a n* and x as a varable subec o manpulaon. From Equaon (6) we calculae he SES by varyng he order of lags from 1 o M o ge he order ha gves he smalles FPE, denoed by m*. The correspondng wo FPE dmensons are gven by: FPE( n*, m) T n* m 1 SSE( n*, m) T n* m 1 T (7) wh m denong he order of lags of x() varyng from 1 o, and n* s he opmum number of lags deermned from Equaon (5). The followng concluson s drawn: energy ( x ) Grangercauses employmen ( y ), f FPE (n*, m*) < FPE (n*). The drecon of causaly employmen and energy consumpon can be esmaed by repeang he same procedure and usng he energy equaons below: ( 1 x x e1 (8) 1 M ( 1 x x y e2 (9) 1 1 Thus, wh he combnaon of he defnon of Granger causaly and he creron of FPE, Hsao (1981) mehod could allow o ener wo or more varables n he equaon wh dfferen numbers of lags. The resul s ha we reduce he number of lags o esmae. Inegraon, saonary and co-negraon Hsao's verson of Granger causaly requres ha all varables are saonary. Hence he frs sep s o es he saonary of varables. The Phllps-Perron (1988) es deermnng he level of negraon s used n hs sudy

4 Issues Bus. Manag. Econ. 196 Tables 1. ess on he levels of negraon of he dfferen varables of he sudy Varables PP value Crcal values GDPE CE * EP * * Sgnfcan a 1% Table 2. Resuls of un roo ess of Phllps-Perron wh frs dfferenced daa. Varables PP value Crcal values GDPE * * Sgnfcan a 1% Table 1 and 2. The Phllps-Perron (PP) es allows o ake no accoun boh auocorrelaon and heeroscedascy of errors, for whch s robus for a varey of seral correlaon and me-bound heeroscedasces. Problems assocaed wh arfcal regresson always mpose o carry ou saonary verfcaon ess of he seres before he esmaon process. The approach of Engle and Granger (1987) frs recommends esng he levels of negraon x and y o ensure he saonary of each varable. In case of nonsaonary of varables, he level mus be dfferenaed accordng o he order of negraon before esmang usng he saonary seres. The concep of co-negraon may be defned as a on movemen over a long perod of wo or more economc varables. Accordng o Engle and Granger (1987), when wo varables x and y are each negraed of order 1,.e. I (1), one would expec a lnear combnaon and hence a random walk. However, s parcular propery may occur ha her lnear combnaon s saonary,.e., I (), n whch case he wo varables x and y are called conegraed. The es of co-negraon s carred ou usng Equaon (3) above. Also, Granger represenaon heorem saes ha when wo varables are co-negraed (.e. a longerm equlbrum relaonshp exss beween hem), hen he mbalanced relaonshp a shor erm beween he wo varables can always be represened by a model correcon error. Daa used Before presenng he emprcal resuls, we descrbe he daa used. The daa are annual and concern he GDP per employee or GDP per person employed.e. he gross domesc produc (U.S. $ consan 199 PPP) dvded by oal employmen n he economy (GDPE), employmen (EP ).e. rao of employmen o populaon of people aged over 15 years, and energy consumpon (EC) or energy use (k of ol equvalen). Seres ha are aggregaed daa of WAEMU member counres from 1979 o 21 were obaned from he World Bank s daabase. The curves below show he evoluon of he respecve varables. Fgure 1. above shows he evoluon of he hree varables used n he sudy. I does no appear a perfec se of movemen beween hese varables. However, he varables Employmen and energy consumpon show a ceran smlar evoluon. More elaboraed ess are performed o denfy he relaonshp beween hese dfferen macroeconomc varables. RESULTS Tess of Granger causaly Tables 3 and 4 show he resuls of he Granger causaly ess beween he varables GDP per employmen (GDPE) and Energy Consumpon (EC) on one hand, and he Energy consumpon and Employmen (EP) on he oher hand. The es used s he Hsao verson of he Granger causaly ess. We ran he model wh dfferen levels of lags, whch ofen led o conflcng resuls. Ths arbrary choce of ranges of lags and / or pre-flerng remans an open queson. To overcome hs falure, he Hsao approach (1981) s used n hs sudy. The resuls are repored n Tables 3 and 4 whle he resuls on he Fscher sascs are repored n Tables 5 and 6. As saed above, when FPE (n*, m*) < FPE (n*), hen he produc per ob (GDPE) Granger causes energy consumpon. In Table 3, he resuls show ha snce energy consumpon s < herefore GDPE causes o he Granger he energy consumpon. Ths resul s confrmed by he sascal F es n Table 5 ndcang ha economc acvy sgnfcanly affecs energy consumpon (a 1%). Conversely, for he GDPE equaon

5 Energy Consupon and RealGDP/Employee Employmen Ouédraogo and Hassane Energy consumpon (n KT ol equvalen) RealGDP/Employee Employmen (number) Fgure 1: Comparave evoluon of he seres ha are nvolved n he sudy Source: Daabase of he World Bank (212) Table 3. Resuls of he Hsao verson of he ess of Granger causaly The equaon of GDPE: (3) > (1) EC does no cause GDPE The equaon of he energy consumpon: (1) < (8) GDPE causes EC The values n he parenheses represen he opmal lags Table 4. Resuls of he Hsao s verson of he ess of Granger causaly The equaon of employmen: (1) > (1) CE does no cause EP The equaon of he energy consumpon: (1) < (8) EP causes EC The values n he parenheses represen he opmal lags. (Table 3), > , herefore appears ha energy consumpon does no cause GDPE n he sense of Granger. The resuls n Table 3 ndcae ha he GDPE varable causes he Granger o cause he varable energy consumpon. The resuls n Table 4 show ha he varable employmen causes he Granger energy consumpon, whch reveals he drecon of causaly beween he dfferen varables. However, he lack of causaly relaonshp n boh drecons ndcaes no co-negraon relaonshp beween dfferen varables. Ths appears clearly n he resuls of ess of co-negraon. Through he same procedure, we perform he es of causaly beween employmen and energy consumpon n he WAEMU area. The resuls repored n Table 4 ndcae he equaon of employmen; energy consumpon does no cause he employmen Granger. However, for he equaon of energy consumpon (Table 4), he employmen causes he Granger energy consumpon. The resuls n Table 5 are furher confrmed by he F es sascs n Table 6, whch ndcae ha employmen affecs energy consumpon a 1%. Therefore n Tables 5 and 6, he varable GDPE causes

6 Issues Bus. Manag. Econ. 198 Table 6: The F ess of employmen equaon M EP (.9759) (.829)* ( 1 EP EC e 2 The values beween parenheses are of p values. * Sgnfcan a 1%. energy consumpon and employmen also causes energy consumpon. DISCUSSIO Ths sudy examnes he phenomenon of causaly of aggregaed macroeconomc varables of he WAEMU area such as GDP per employee, employmen and energy consumpon. Research has allowed denfyng undreconal relaonshp beween he produc per employmen and energy consumpon bu also beween employmen and energy consumpon. The resuls obaned n hs documen are n lne wh he resuls of smlar sudes on he relaonshp beween energy consumpon and he level of economc acvy (GDP), n parcular he one of Kraf and Kraf (1978) whch fnds causaly gong n he drecon from GDP o energy consumpon for he Uned Saes. I s he same for Yu and Cho (1985) who conduced a sudy on he Phlppnes and Souh Korea. Oher sudes n Souhern Sahara Afrca on he relaonshp beween energy consumpon and economc growh lead o he same resuls. Ths s he case of Tme s work (21), Ambapour Massamba (25) and Jumbe (24), whch respecvely ndcae a undreconal causaly from GDP o elecrcy consumpon n Côe d Ivore, Congo and Malaw. However, he resuls of some sudes such as hose of Okey (29) on Benn, Ivory Coas, Senegal and Togo reveal a lack of causaly beween elecrcy consumpon and economc growh. Ths undreconal causaly from GDP owards energy consumpon can be explaned by he fac ha economc growh n general generaes a hgher ncome per nhaban and herefore an ncrease n overall consumpon as spulaed n he psychologcal law of Keynes. Tme (21) n he case of Côe d'ivore manans ha energy producs are goods of necessy, any ncrease n he naonal ncome lead o hgher consumpon of hese producs. Ths resul also ndcaes ha pror nformaon of GDP help make beer forecass on energy consumpon n he WAEMU area. Undreconal causaly from GDP o energy consumpon could also mean sascally ha energy savng polces can be mplemened whou compromsng economc developmen (Wolde-Rufael, 26). The lack of causaly of energy consumpon o economc growh also has s orgn n he low access of he rural populaon (7% of he workforce) n he WAEMU area o mos of he convenonal energy sources whereas hey consue he vas maory (Kane, 29; Tmé, 21): hese populaons essenally lve on non-mechanzed agrculure, parcularly subssence agrculure. Concernng he relaonshp where employmen causes un-dreconally energy consumpon, research conduced by Akarca and Long (1979) and Murray and an (199) reach he same concluson for he Uned Saes. Oher sudes ncludng Erol and Yu (1987b) and Yu e al. (1988) usng daa from ndusralzed counres have no led o he causal relaonshp beween energy consumpon and employmen. Ths leads o hnk ha he economc acves of developed counres are no hghly nensve n energy, probably because hey are more effcen n her energy consumpon. Ths resul "employmen causes un-dreconally energy consumpon" can be explaned manly by he fac ha any ncrease n employmen n he economy goes wh an ncrease n he producon of enerprses, whch means economc growh. Snce economc growh ncreases naonal ncome; wll herefore resul n he sense of Keynes psychologcal law an ncrease n energy consumpon whch s a necessy n general. I should be noed ha he varous ess showed ha he varables are no co-negraed, whch dd no requre he use of error correcon model. Concluson and Recommendaons Ths arcle revews he Granger causaly beween energy consumpon on one hand and GDP per employmen, and he consumpon of energy and employmen on he oher hand for he WAEMU zone. We used he Hsao s verson of Granger s causaly mehod and Akake FPE creron o deermne he opmal lags. Ths helped oban a beer esmaon of lnks of causaly beween he wo pars of varables consdered. The resuls ndcae a relaonshp of undreconal causaly on one hand and GDP per employmen o energy consumpon and varable employmen o energy consumpon on he oher hand for he WAEMU area.

7 Ouédraogo and Hassane 199 Undreconal causaly from GDP owards energy consumpon could sascally mean ha energy savng measures can be aken whou compromsng economc developmen (Wolde-Rufael, 26). However, he pons ou ha reduced elecrcy consumpon n populaons who have dffcul access o hs resource (ncludng rural populaons n he WAEMU area), s no an opon. Afrcan counres have no ye reached a level of energy ndependence (poor nfrasrucure) o allow a reducon n her consumpon bu hey can preven he negave consequences relaed o he ncreased consumpon of energy and s neffcen use. Insead, by makng dfferen convenonal energy sources more accessble o all, could no only conrbue o reduce povery bu also o mprove he qualy of lfe of populaons and hus lead o economc growh n he wo senses of causaly. Tha means economc growh mproves he qualy of lfe and vce versa. For he fac ha energy consumpon does no cause economc growh reveals low access of rural populaons n he WAEMU counres o dfferen energy sources, should convene o promoe agro-busness and mechanzaon of agrculure n hese counres (Kane, 29). I hen appears ha energy s an mporan facor for he developmen of he WAEMU zone. Therefore, energy polcy n hs area mus ake no accoun he varous producons n he domans of ndusry, manufacurng, consrucon, ranspor ec., whch requres a grea deal of energy o acheve economc and socal developmen of he area whch naurally requres a srenghenng of he energy nfrasrucure. REFERECES Abdel-Khalek G (1988). Income and prce elasces of energy consumpon n Egyp, Energy Econ. 1: Akake H (1969). Fng auoregressve models for predcon, Annals of he Insue of Sascal Mahemacs 21: Akarca AT, Long TV (1979).Energy And Employmen: A Tme Seres Analyss of he Causal Relaonshp, Resources Energy, 2: Ambapour S, Massamba C (25). Crossance économque e consommaon d énerge au Congo : une analyse en ermes de causalé. Documen de Traval n 12, Brazzavlle. Anderson KP (1973). Resdenal demand for elecrcy: economerc esmaes for Calforna and Uned Saes, J. Bus. 46 (3): Asafu-Adaye J (2). The relaonshp beween energy consumpon, energy prces and economc growh: me seres evdence from Asan developng counres, Energy Econ. 22: Burney A (1995). Socoeconomc developmen and elecrcy consumpon: a cross-counry analyss usng he random coeffcen mehod, Energy Econ. 17 (3): Cheng BS, La TW (1997). An nvesgaon of co-negraon and causaly beween energy consumpon and economc acvy n Tawan, Energy Econ. 19: Engle RF, Granger CWJ (1987). Co-negraon and errorcorrecon: represenaon, esmaon and esng, Economerca 55(2): Erol U, Yu ESH (1987b). Tme seres analyss of he causal relaonshp beween U.S. energy and employmen, Ressources and Energy 16: Geweke e al. (1983). comparng alernave ess of causaly n emporal sysems, J. Econ., pp Gulkey DK, Salem MK (1982). Small sample properes of ree ess of Granger causal orderng n a bvarae sochasc sysem, Rev. Econ. Sa., 64: Hsao C (1987). Auoressve modellng and money ncome causaly deecon, J. Moneary Econ., 7: Jumbe CBL (24). Co-negraon and causaly beween elecrcy: consumpon and GDP: emprcal evdence from Malaw, Energy Econ. 26: Kane CS (29). Demande d énerge e crossance économque dans l UEMOA : Une analyse sur panel héérogène non saonnare. Revue Afrcane d Inégraon, Vol 3, n 1. Kraf J, Kraf A (1978). On he relaonshp beween Energy and GP, Journal of Energy and Developmen, 16: Mash AMM, Mash R (1997). On emporal casual relaonshp beween energy consumpon, real ncome and prces: some new evdence from Asan-Energy Dependen ICs based on a mulvarae co-negraon vecor error correcon approach, J. Pol. Modellng 19 (4): Munasnghe M (198). Inegraed naonal energy plannng (IEP) n developng counres, a. Resour. Forum 4: Murray DA, an GD (199). The energy and employmen relaonshp: a clarfcaon, The Journal of Energy and Developmen 16: Okey MK (29). Consommaon d énerges e crossance du PIB dans les pays de l UEMOA : Une analyse en données de panel. Documen de Traval, Unversé d Abdan-Cocody. Phllps PCB, Perron P (1988). Tesng for un roo n me seres regresson, Bomerca, 75: Sacko I (24). Analyse des lens enre crossance économque e consommaon d énerge au Mal, CERFOD-FSJE, Unversé du Mal. Samolds J, Mrolopulos CS (1984).Energy and economc growh n ndusralzed counres, Energy Econ. 6: Tmé EHH (21). Consommaon d Élecrcé e Crossance Économque en Côe d Ivore. Mémore de fn d éudes, Maser GPE, Abdan. Wolde-Rufael Y(26).Elecrcy consumpon and economc growh: a me seres experence for 17 Afrcan counres. Energy Pol. 34: Yang HY (2).A noe on he causal relaonshp beween

8 Issues Bus. Manag. Econ. 2 energy and GDP n Tawan. Energy Econ. 22: Yu ESH, Cho JY (1985) The casual relaonshp beween energy and GDP: an nernaonal comparson, J. Energy Dev. 1: