外文文献翻译-发展中国家能源与经济增长的因果关系

PAGE26外文文献翻译译文一：Energy,economicgrowthandcausalityindevelopingcountries学生姓名指导教师分院信息分院专业名称统计学班级统计学号发展中国家能源与经济增长的因果关系基于坦桑尼亚和尼日利亚的案例研究摘要：能源在经济发展中的确切作用是一个尚有争议的辩论。现有的实证研究产生了不同的结果：一些人认为能源和其他生产要素之间是互补性关系，而其他人表示，能源可以替代其他生产要素。通常情况下，这些研究主要集中在发达国家，有一种解释是供给约束和价格刚性使任何因素换成研究在发展中国家毫无意义。虽然这种技术是有用的实证分析，因为没有机制的存在表明变量之间的因果方向。但是，这限制了范围的政策分析。需要确定，在发展的能源消费和收入增长之间的因果方向发展中国家是压倒性的。除了从能源在经济发展中的作用提供了进一步的深入了解，提供政策分析，更清楚地了解能源供给约束对经济增长可能带来的影响。本文探讨的因果关系的方向之间的能源消费与经济增长（以本地生产总值及本地居民生产总值）以尼日利亚和谭坦桑尼亚为例。结果显示了能源和经济增长之间的因果关系。其含义是，除非缓解能源供应的限制，否则对这些国家的经济增长和发展将仍然是难以捉摸的。由于相似的经济特征和相同的能量为其他发展中国家提供见解，我们的研究结果支持认为，能源在经济发展中起着关键的作用。关键词：能源，经济增长，因果关系由于日益认识到能源的重要性，国家的经济发展的需要确定能源和经济增长之间的关系。这已经导致许多人质疑传统的新古典生产函数分析，其中土地，劳动力和资本被确认为生产的主要因素。这种分析一直延伸到包括能量变量。然而，能源的影响基准的幅度对经济的作用引起了宏观经济学家的激烈辩论。因此，他们已经作出努力来发现能源和其他生产要素之间的确切关系，判断是否能量补充或替代其他生产要素。这些知识将显著影响能源政策的制定，除非解决能源在经济增长中的作用和意义还不明朗。首先出现的是宏观经济学家的解释是在1973-74和1978年至1979年成品油价格上调对全球经济的“供给冲击”达成共识。Rasche和Tatom（1977）探讨了能源价格高企对经济增长可能产生的不利影响，通过指定一个新的类型的生产函数。此功能包括一个能量除了确定常规的变量的变量以上。他们能够与美国的数据显示，不仅有能源价格上涨产生潜在的国民生产总值下降的趋势，但已经有很多实际的输出能力在任何时间，在美国经济史。奥肯（1974年，1975年），另一方面，驳斥了这种说法，理由是能源构成，与其他生产投入相比，只是一个相对“较小的成本份额”总产出。在这种情况下，能源价格变动对经济的影响相对较小，尤其是考虑到帐户提供其他替代的可能性生产因素。隐式，已被认为是完美的要素替代能源。假设替代系数的大小是这场辩论的一个重要考虑因素。它似乎假定者奥肯（1974年，1975年）的系数是比通过的Rasche-Tatom（1977）的高得多。因此，能源价格的上涨将导致资本替代劳动。其他支持这一观点。佩里（1975，1977）认为，“这是很难相信，能源价格高企会影响生产率和产出增长”，因为它只是其中的许多组件生产。显然，辩论的直接影响能源价格高企或其他能源供应对经济增长的约束可能有被夸大了“莫须有”的。我明确，有一个先决条件，现有的理论经济生产力的发展趋势，应适当地处理能源危机。这个说法，似乎Rasche-Tatom型的生产函数是不必要的，多余的。事实上，类似的扣除已由吉尔施和沃尔特（I983）。他们观察到，这依赖于欧佩克1973-74和1979-80的价格上涨被认为辩论。他们争辩说，当这件事被视为国内税收的增加，就很难明白，为什么一定不同通货紧缩的财政政策对经济的影响。虽然吉尔施和沃尔特（1983）和佩里（1975年，1977年）之间有一个共识，对传统的经济理论来解释生产力趋势的能力，他们不同意的能源价格对经济的影响。佩里（1975，1977）认为影响最小，吉尔施Woiter（1983）认为是“间接”的影响，其大小或幅度取决于政府政策的有效性。结果分析由此可见，上述实证分析强烈坚持我们的理论，能源消费在国民收入的增长是相辅相成的。非洲的能源结构密切监察蒙上巨大的怀疑其能否实现可持续的经济增长和发展，赋予其能源问题。尽管其巨大的商业性能源储备（水电，原油，天然气和煤炭），percapitaenergy消费量位居世界最低的。常规或生物质能（主要是木材和木炭）占70％以上的能源消耗总量，而在亚洲和拉丁美洲，此源帐户分别只有35％和25％的（Davidson，1992）。虽然从这个来源完全满足农村能源需求，只有10％的城镇人口使用的商业能源（安德森和菲舍维克，1984年）。由于作用城镇人口在的经济增长Kahnet（1986），在保持这一增长势头，满足城市的能源需求是必不可少的。然而，从其他经济部门一方面对生物质的竞争性需求，另一方面，消耗的速度加快，导致严重的能源短缺。同样标明相关的私人成本和社会成本，被称为第一次能源危机（Mazava，1981）。将它与一个有它的起源从1973年的成品油价格上调的第二次能源危机已经离开了大陆巨大的能量赤字，这被证明是非常难以弥合的。在商业能源部门，短缺比比皆是。这里的主要因素，由于这些国家的净能源进口国之一，是财政上的限制。政策的两难中心圆一个事实，即能源投入生产部门的经济活动中是非常重要的-农业，特别是工业部门。与此同时，出口收汇几乎足以影响能源进口。总债务服务的89％和79％的石油进口分别与一些国家如贝宁和坦桑尼亚的例子加强了这些国家面临的能源困境。商业能源短缺的交通网络瘫痪，破坏商业和工业能力，导致不理想的国内家电消费，这对产出，就业，收入和消费带来的束缚。很明显，从这个讨论中，非洲不能住如此巨大的能量赤字，同时实现有意义的成长和发展。鉴于这一事实，需要庞大的投资，以扩大非洲的能源约能力。世界银行估计，这将每年花费US$28亿美元的投资，必须持续超过10年的时间内，以便在非洲的能源供应能力（世界银行，1988年）每年5％的温和扩张。这些经济体的不稳定状态，例如出口收入的变异规则产生如此巨大的金额从内部人士透露的可能性。因此，多边和单边的组织可以发挥关键作用，调动了大量的投资需要刺激撒哈拉以南的能源部门。发达国家和发展中国家是不利于基本经济目标和目标的充分就业，经济增长，低廉的价格和更高的生活水平，这是世界各国政府的优先级之间的差距越来越大。目前，这种巨大的差距征收卷上的世界贸易和全球经济衰退的影响已成为一个主要的主要制约因素。因此，存在于发达国家，以协助将这些网络，以提高他们有效地参与全球经济活动的繁荣和可持续的经济援助受助人的部分。在这方面，与能源投资的好处是相互的。显然，能源和经济增长之间的关系是互补的。努力在subSaharan非洲国家的经济现代化，必须采取长期的能源问题。在这方面，随之而来的能源需求增长战略必须进行验证。否则，当前和未来的增长前景将受到能源短缺。Energy,economicgrowthandcausalityindevelopingcountriesThedebateaboutthepreciseroleofenergyineconomicdevelopmentremainscontentious.Existingempiricalstudieshaveproducedvaryingresults:somehavearguedthecomplementaritybetweenenergyandotherfactorsofproduction,andothershaveindicatedthatenergycanbesubstitutedforotherfactorsofproduction.Commonly,thesestudieshavefocusedprimarilyonthedevelopedcountries,oneexplanationbeingthatsupplyconstraintsandpricerigiditiesrenderanystudyonfactorsubstitutionsindevelopingcountriesmeaningless.However,thefunctionalrelationshipbetweenen-ergyconsumptionandincomeindevelopingcountriesisconstantlyinvestigatedwiththeuseofregressiontechniques.Whilesuchtechniquesareusefulinempiricalanalysis,nomechanismexistsforindicatingcausaldirectionsbetweenvariables.Thislimitsthescopeforpolicyanalysisandprescription.Theneedtoidentifycausaldirectionbetweenenergyconsumptionandincomegrowthindevel-opingcountriesisoverwhelming.Apartfromprovidingfurtherinsightsintotheroleofenergyineconomicdevelopment,itprovidespolicyanalystswithaclearerunderstandingofthelikelyimpactofenergysupplyconstraintsoneconomicgrowth.Thisarticleexaminesthecausaldirectionsbe-tweenenergyconsumptionandeconomicgrowth(proxiedbyGDPandGNP)forNigeriaandTan-zania.Theresultsshowasimultaneouscausalrelationshipbetweenenergyandeconomicgrowthforbothcountries,theimplicationbeingthat,unlessenergysupplyconstraintsareeased,economicgrowthanddevelopmentwillremainelusivetothesecountries.Givensimilareconomiccharacteristicsandprofilingthesameenergyscenarioforotherdevelopingcountries,ourfindingsupportstheviewthatenergyplaysakeyroleineconomicdevelopment.Copyright©1996ElsevierScienceLtd.Keywords:Energy;Economicgrowth;CausalityTheneedtodeterminetherelationshipbetweenenergyandeconomicgrowthderivesfromtheincreasingrealizationoftheimportanceofenergytotheeconomicdevelopmentofnations.Thishasledmanytoquestiontheconventionalneoclassicalproductionfunctionanalysiswhereland,labourandcapitalarerecognizedasthemainfactorsofproduction.Thisanalysishasbeenextendedtoincludeanenergyvariable.However,themagnitudeofenergy'sinflu-enceontheeconomyhasbeenhotlydebatedbymacro-economists.Consequently,effortshavebeenmadetodiscovertheexactrelationshipbetweenenergyandotherfactorsofproductionastowhetherenergycomplementsorsubstitutesotherfactorsofproduction.Suchknowledgewillhavesignificantbearingonenergypolicyformulation.Unlessthisisresolved,theroleandsignificanceofenergyineconomicgrowthremainsclouded.Firstthereisconsensusamongstmacroeconomistsontheinterpretationofthe1973-74andthe1978-79oilpriceincreasesas'supplyshocks'totheglobaleconomy.RascheandTatom(1977)exploredthepossibleadverseeffectsofhighenergypricesoneconomicgrowthbyspecifyinganewtypeproductionfunction.Thisfunctionincludesanenergyvariableinadditiontotheconventionalvariablesidentifiedabove.TheywereabletoshowwithUSdatathatnotonlyhadenergypriceincreasesexerteddecliningtrendsonpotentialGNP,butthatactualoutputhasbeenmuchclosertocapacitythanatanytimeinAmericaneconomichistory.Okun(1974,1975),ontheotherhand,refutedthisclaimonthegroundsthatenergy,comparedwithotherproductioninputs,constitutesonlyarelatively'smallcostshare'intotaloutput.Thisbeingthecase,energypricechangeswillhavearelativelysmallimpactontheeconomy,especiallytakingintoaccountsubstitutionpossibilitiesprovidedbyotherfactorsofproduction.Implicitly,perfectfactorsubstitutionhasbeenassumedbetweenenergy,labourandcapital.Thesizeassumedforthesubstitutioncoefficientisanimportantconsiderationtothisdebate.ItappearsthatthecoefficientassumedbyOkun(1974,1975)ismuchhigherthanthatadoptedbyRasche--Tatom(1977).Thus,anincreaseinenergypriceswillresultinthesubstitutionoflabourforcapital.Othershavesupportedthisview.Perry(1975,1977)hassuggestedthat'itishardtobelievethathighenergypricescanaffectproductivityandoutputgrowth'sinceitisjustoneofmanyproductioncomponents.Evidently,thedebateonthedirectimpactofhighenergypricesorotherenergysupplyconstraintsoneconomicgrowthmayhavebeenexaggeratedand'unwarranted'.Im-plicitly,thereisapresuppositionthatexistingtheoreticaleconomicapproachestoproductivitytrendsshoulddealadequatelywiththeenergycrisis.Giventhisassertion,itwouldseemtheRasche--Tatomtypeproductionfunctionisunnecessaryandsuperfluous.Indeed,similardeductionshavebeenmadebyGierschandWolter(I983).TheyobservedthatthisdebaterestsonhowtheOPEC1973-74and1979-80priceincreasesareperceived.Theycontendthatwhenthisincidenceistreatedasdomestictaxincreases,itbecomesdifficulttoseewhytheeconomicimpactsshouldnecessarilydifferfromthoseofdeflationaryfiscalpolicies.WhilethereisaconsensusbetweenGierschandWolter(1983)andPerry(1975,1977)ontheabilityofconventionaleconomictheoriestoexplainproductivitytrends,theydisagreedontheeconomicimpactofenergyprices.WhilePerry(1975,1977)arguedforaminimalimpact,GierschandWoiter(1983)believedtheimpacttobe'indirect',whosesizeormagnitudedependedontheeffectivenessofgovernmentpolicies.Evidently,theseresultshavebeeninfluencedbythemethodsofanalysisemployedasshowninTable!.BemdtandWood(1975)arguedthatwhileenergyandlabourmaybesubstitutable,thecomplementaryrelationshipbetweenenergyandcapitalraisesitsimportancefarmorethanitscostshare.Implicitly,thedynamicimpactofthisrelationshipforoutputandproductivityunderlinetheimportantinfluencethatenergyhasoneconomicgrowth.HudsonandJorgenson(1974)similarlyechoedthisviewwhentheyfoundthattheoutputcompositionoftheUSAdidchangewithenergypricemovements.InTable1,itisevidentthatenergyandlabour,ontheonehandandontheother,capitalandlabouraresubstitutableasarguedbyOkun(1974,1975).Thus,itispossibletocompensateforanenergyinduceddeclineinnationalincomebysubstitutinglabourorcapital.However,thereisnounanimousagreementontherelationshipbetweenenergyandcapital;ratheradivergenceoffindingsarereported.BerndtandWood(1975),HudsonandJorgenson(1975)andMatsuietal,1978(ascitedinSusukiandTakenaka(1981))foundenergyandcapitaltobecomple-mentarywhileGriffin(1979)foundenergyandcapitalsub-stitutable.However,lookingatthetypeofdataused(timeseriesversuspooleddata),thedifferencesinresultscanbeexplained.Usually,timeseriesanalysisinfershort-runrelationshipsandpooleddatapointtolong-runsituations.Itcanbearguedthereforethatenergyandcapitalarecomplementaryintheshortrunbutbecomesubstitutableinthelongrun.DevelopingcountriesInthecaseofthedevelopingcountries,aprioriobservationmaysuggestthattheanalysisofOkun,(1974,1975)andthatof(Perry1975,1977)apply,giventhescaleandsizeofthe'modern'sectorintotalproductiveactivities;thesubstitutionpossibilitiesbetweenlabourwhichis'surplus',andtechnologythatisintermediateandrudimentary.Onacriticalnote,thesecharacteristicsarelikelytointensifyenergyconsumptionintheeventofthesecountriesexperiencinggrowthineconomicactivities.First,theperfectsubstitutionassumedbetweenlabourandenergyisdoubtful.Evenifweweretomakeanextremeassumptionthattheoppositeisthecase,intheabsenceofanydefinedoptimumlimittoprofit,thedemandforhigherwagesandbetterworkingconditionswillhinderanysubstitutionpossibilities.Second,therarityofskilledlabourinunderdevelopedeconomiescastseriousdoubtsonanysubstitutionpossibilities.Givensuchsupplyconstraints,capital-laboursubstitutionbecomesinevitable.Furthermore,ifthenatureoftechnologiesemployedareconsidered,thefactthatthesearelargelyintermediatetechnologiesthatareenergyintensivehighlightstheenergyintensityoftheiruseinproductionactivities.Thus,itisnotjustthedoubtfulsubstitutionpossibilitybetweenlabourandcapitalthatistheproblemhere,butratherthattheenergyimplicationoftheabsenceofsuchapossibilitydemandssomeattention.Itisthisfactthatunderlinesthecomplementaritybetweenenergyandcapitalandtheattendantimplicationsforenergyconsumptionintensityindevelopingcountries.Alsocriticaltothedebateisthecostassociatedwithsubstitutingcapitalforenergywhichhasnotreceivedadequateconsiderationinthedebate.Inordertoenhancecapital-energysubstitutionpossibilities,massiveinvestmentinplantsandequipmentisnecessarytoreplacetheenergyintensiveintermediatetechnologywidelyinuse.Thereisalsoanadditionalcostassociatedwithdevelopingthehumanre-sourcebasethatisnecessarytomaximizetheenvisagedenergysavingsthatwouldaccruefromtheintroductionofefficienttechnologies(Cecelskietal,1979).Ifsuchtransitioncostsweretoproveprohibitive,developingcountrieseconomieswouldbeexposedtoseriousenergyconstraints.Equallyimportantarethezerosubstitutionpossibilitiesthatexistbetweencommercialandtraditionalenergywithrespecttocertainindustrialandhouseholdactivities,partlybecauseofsupplyconstraints,butmainlyduetocookinghabitsandtraditions.Inotherareaswherethesepossibilitiesexist,theenvironmentalcostsintermsofdesertificationanddroughttendtocastseriousdoubtsonitssustainabilityasalong-termenergystrategy.Evidently,itisobviousfromthelatterpointthattheissueofcomplementarityandsubstitutabilitybetweenenergyandcapitalindevelopingcountriesislargelyirrelevant.Instead,wewouldarguethatforthedevelopingcountries,energycomplementscapital.Giventhedesireofdevelopingcountriestoincreasevalue-addedcontributionstoprimarycommodityexportsontheonehand,andontheother,thesmallsubstitutionpossibilitiesbetweencapitalandlabour,capitalandforeignexchangescarcitieswillcombinetocomplicateenergyscenariosinthesecountries(Dunkerleyetal,1981).Severalstudiesundertakenforthedevelopingcountrieshaveindicatedstrongrelationshipsbetweenenergyandeconomicgrowth(Leachetal,1986;Ang,1987;Dunker-ley,1986;Desai,1986;Pearson,1987;Arima,1994).Commontothesestudiesisthefindingthatincomeelasticityofenergydemandgenerallytendstobehighlyelasticandgreaterthanunity,whereasestimatedpriceelasticitieshavebeeninsignificantlydifferentfromzeroandveryinelastic.Theimplicationbeingthatittakesmorethana1%increaseinenergyconsumptiontoproduceanincreaseof1%nationalincome.Analogously,priceelasticityofenergydemandisveryinelasticsincethequantityofenergydemandedisfarlessresponsivetopricechanges.Thesefindingscontrastwiththosefoundfortheindustrializedcountrieswhereincomeelasticitiesofenergydemandgenerallytendtobelessthanone(Nordhaus,1977;Hamilton,1977;Griffin,1979).Intuitively,andgiventherightinstitutions(technicalandfinancialresources,investmentinhumancapital,andthecapacityforpolicyfomulationandimplementation),thedevelopedcountrieshavesuccessfullydecoupledenergyconsumptiontrendsfromeconomicgrowth.Thesearethenecessaryprerequisitestofactorsubstitutionpossibilities.Theveryabsenceofthesefavourableconditionsinthedevelopingcountrieslargelyexplaintheirenergyconsumptionintensity.TheeconomiesandenergysectorsofNigeriaandTanzaniaTheeconomiesofNigeriaandTanzaniatypifythoseoftherestofsub-SaharanAfrica.Theyarelargelymonocultural,relyingononeortwoprimarycommodityexports.Theagriculturalsectorisundevelopedandlargelymanagedonasubsistencebasis.Thisapart,thesectorischaracterizedbylowcapitalformationrequiringfoodimportsthatareoftenusedtoaugmentfallingdomesticproduction.WhileNigeria'sindustrialsectorcontributes43%oftotalGDP,Tanzaniacontributesonly5%.Generallythough,thesectorinbothcountriesexhibitssimilarcharacteristics,beingdominatedbyimportsubstitutingfootlooseassemblytypeindustries.Consequently,fewbackwardorforwardlinkagesexistbetweentheindustrialsectorandtherestoftheeconomy.Aperennialbalanceofpaymentdeficit,broughtaboutlargelybycommoditypricefluctuationandadversetermsoftradebetweenprimarycommoditiesexportsandmanufacturedimports,isacommonfeatureofbotheconomies.Increasingly,externalborrowingsandfinancialaidhavebecomedominantinmacroeconomicplanning.Consequently,thesecountrieshavebecomeheavilyindebted.Forexample,totaldebtsfor1992stoodatUS$30998millionandUS$6715millionforNigeriaandTanzaniarespect-ively(WorldBank,1994).ThemagnitudeoftheimpactoneconomicgrowthhascauseduneaseattheEconomicCommissionofAfrica,giventheincreasingproportionofexportproceedsdevotedtodebtservicing(ECA,1988).Forexample,totalexternaldebtstoexportswere25.1%and12.0%forNigeriaandTanzaniarespectivelyin1992.Furthermore,externaldebtasaproportionofGNPin1992was110.7%and268.4%respectivelyforthetwocountries(WorldBank,1994).Itisnocoincidencethateconomicgrowthhasvariedwithforeignexchangeavailabilityinthesecountries(Singh,1986).Theenergysectorsofbotheconomiesareundevelopedandcharacterizedbyshortagesandsupplyconstraints(Ebohon,1992).WhileNigeriaisanetoilexporterandflaresmorethan90%ofitsgasreserve,energyshortageissomarkedthatpowerinterruptionsandfuelshortagesarecommonplace(Ebohon,1992).Thisisattributabletoinadequateenergyinfrastructure,lackofspareparts,manpowershortageandinefficientmanagement.InTanzania,itisrathertheinabilitytosustainthehugeenergyimportbillsthatislargelyresponsibleforenergysupplyshortages.Energyrelateddebt,asaproportionofTanzania'stotaldebtobligations,ismorethan80%.Withoutacommensurateex-pansioninexportsandexportrevenues,suchhugeenergyexpenditureremainsunsustainable.Thisbecomesaviciouscircleandisadilemmabecauseoftheenergyimplicationofboostingexports.Giventheseconstraints,itcomesasnosurprisetofindthatupto68%andinsomecasesupto90%ofdevelopingcountriesurbanpopulationdependonwoodfuelandotheragriculturalbiomassresiduesforenergy(Millingtonetal,1994;AndersonandFishwick,1984).Giventhevirtualdependencebyruralpopulationonthesefuelsources,thecombinedenvironmentalimpactontheonehand,andontheother,supplydifficultiesarehavingnegativeimpactsonoutputandgrowth.Thus,theneedfor,andthespeedbywhichsolutionsmustbesoughthaveneverbeengreater.Fromsuchurgencytoact,theneedtotodeterminecausaldirectionsbetweenthevariablesisborn.Causalitytestforenergy-incomerelationshipAsdiscussedabove,sinceregressionanalysistellsusnothingaboutthedirectionofcausalityintherelationshipbetweentwovariables,itremainssimplistic.Inthisregard,thecausalityestimatingtechniqueofferscertainadvantages.Understandingthecausaldirectionbetweenenergyconsumptionandeconomicgrowthiscrucialtoeffectiveenergymanagement,especiallyinthedevelopingcountrieswheredifficultchoiceshavetomadebecauseofthecompetingdemandsforscarceresources.ThecausalitytestdevelopedbyGranger(1969)isemployed.Ourresultsstandtoachievetwothings.First,itwillhelptoindicatecausaldirectionsbetweenthetwovariablesatdiscussion.Forexample,ifaunidirectionalcausalityexistsfromGDPtoenergy,itwouldmeanthatincreasesinenergyconsumptionisaffectedbyrisingGDP.Foranen-ergyanalyst,acasemayexistforfocusingonthecomponentsandstructureofGDPinordertominimizetheadverseeffectofenergyconstraintsonitssustainability.Thisisofpolicysignificancetoacountryatanearlystageofdevelopment.Duringthisperiod,lifestylesaresimple,produc-tionislabourintensiveandsubsistenceandtransportinfrastructureandurbanplanningareatanincipientstageofdevelopment.Mostdevelopingcountries,especiallytheleastdeveloped,arepresentlyatthisstageofdevelopment.Ontheotherhand,asimultaneouscausalitywillvalidatetheaprioriassumedcomplementaryrelationshipbetweenenergyandcapital.Itisduringthisstagethatacountrybecomeslockedintohabitsofhighenergyconsumption,wheneconomicgrowthcannotbeachievedwithoutacommensurateamountofenergyconsumption.Atthisstage,onlythosecountrieswiththerightinstitutions,energysav-inginvestmentsandcapacitytoformulateandimplementpoliciescaneffectivelymanageitsenergyproblems.Itcanbeseenthataknowledgeofthecausaldirectionsbetweenenergyconsumptionandeconomicgrowthisvitaltoseekingsolutionstotheproblemsposedbyenergysupplycon-straintsinthedevelopingcountries.ModelspecificationGranger's(1969)causalitytestregressesavariableyonalaggedvalueofitselfandanothervariablex.lfxissignificant,itmeansthatitexplainssomeofthevarianceofythatisnotexplainedbylaggedvaluesofyitself.ThisindicatesthatxiscausallypriortoyandsaidtodynamicallycauseorGrangercausey.Themodelcanbespecifiedaccordinglyasfollows:Thetaskofchoosingthelead/laglengthisarduousespeciallywhenthenumbersofobservationsarerelativelysmall.Giventhisfact,andinachievingcovariance-stationarityorwhitenoiseprocess,firstdifferencewastakenandusedtodetrendthedata.Thus,Equation(1)isthenrewrittenas:andbyanalogy,ForaunidirectionalcausalitytoexistfromEtoY,theestimatedcoefficientonlaggedEinEquation(2)shouldbesignificantlydifferentfromzeroasagroup()andthesetofestimatedcoefficientsonlaggedY()inEquation(3)shouldnotbesignificantlydifferentfromzero.Iftheco-efficientsoflaggedEandYaresignificantlydifferentfromzero,iein(2)andin(3),simultaneouscausalityissaidtoexist.Ontheotherhand,wherebothsetsofcoefficientsarenotsignificantlydifferentfromzero,EandYaresaidtobeindependentofeachother.Dataused,lag/leadspecificationTheperiodcoveredforNigeriawasbetween1960-84,and1960-81forTanzania.ThedatawasobtainedfromtheInternationalFinancialStatistics,Yearbook1986;theUnitedNation'sEnergySupply,SeriesJ,1960-70and1971-75;andtheUnitedNationsYearbookofNationalAccounts,variousyears.Asdiscussedabove,firstdifferencewastakenandusedtodetrendthedatainordertoachievecovariancestationarityorwhitenoiseprocess.TheF-statisticwasusedasastandardruleforacceptingorrejectingthenullhypothesisinfavourofthealternativehypothesis.RejectingthenullhypothesiswouldindicatethattheinclusionofpastvaluesofEintheregressionprovideuswithabetterexplanationofcurrentvaluesofYthanwhenexcludedandviceversa.TheDW-statisticwasusedtotestthepresenceofautocorrelationinthemodel.ResultsFromTable2,wecanobservethatthenullhypothesis(increasedeconomicactivitydoesnot'Granger-cause'anincreaseinenergyconsumption)cannotberejectedforTanzaniainviewoftheestimatedstandarderrors.ThismeansthattheinclusionofpastvaluesofYandEintheregressionsprovidedabetterexplanationofcurrentvaluesofEandYthanwhenexcluded.Indeed,bythismethod,asimultaneouscausalrelationshipcanbeseentoexistbetweenenergyconsumptionandeconomicactivities,proxiedbyGDPandGNP.Giventhepredominanceofcashcropsandagriculturalexportsintotaleconomicactivities,thiscomesasnosurprise.However,aprioriobservationmaysuggestlowenergyuse;butthecrucialroleoffertilizers,processing,andtransportinproductionactivitieshighlighttheimportanceofenergy.Indeed,energyrelatedtransportandotherdifficultieshaveresultedinhugepost-harvestlossesinthesecountries(MakhijianiandPoole,1975).Thus,thisfindingservestostrengthentherelationshipbetweenenergyandnationalincomeinTanzania.Theimplicationisthatenergyshortagescanseriouslyhindereconomicgrowthanddevelopment.Asindicated,theF-statisticisnotusuallyusedasameasureofsignificanceintheGrangertestbutwehaveusedittotestwhethertheinclusionofpastvaluesintheregressionenhancesthesignificanceofthewholeregression.TheF-testsforalltheregressionsweresignificantatthe5%levelofsignificance.ThefiguresinparenthesisareDW-statisticswhichwereusedtotestforthepresenceofautocorrelationandthevaluesindicatetheabsenceoffirstorderautocorrelation.TheneedforaninstantaneouscausalitytestfollowsfromtheobservationsmadebyGrangerthatifadislocatedsequenceoccursinthedata(ieifYcausesEtooccurwithoneperiodlag,insteadatwoperiodlagwasobserved)itcouldresultin'spuriouscausality'.Thiswillcompoundtheproblemsofidentifyingthedirectionofcausality,especially,aunidirectionalone.PierceandHughes(1977)arguethattheGrangertypetestcannothandletheproblemsofcontemporaneousinnovations'ononeorallthevariablesused.Suchinnovationsarealwayspresentinthefieldoftechnologynotleastenergy.Forexample,effectiveconservationmeasures,efficientenergyenduseappliancesandchangesinthelawsaffectingtransportandurbanplanningwillaffectenergyintensityrelativetoeconomicactivities.Accordingly,PierceandHughes(1977)suggestedthatonewayofaccountingfor'contemporaneousinnovation'istotestforinstantaneouscausality.Usingthismethod,wehavetestedwhethertheinclusionofacurrentvalueofYwithitspastvalueswillprovideabetterpredictionofcurrentvaluesofEandsimilarlyifwearetestingforinstantaneouscausalitybetweenEandY.FromtheresultsshowninTable3,thecausalitybetweenenergyandGNPisnotinstantaneous,butthatbetweenGNPandenergy,GDPandenergyaswellasenergyandGDPareinstantaneous.Thisisnotsurprisingsinceadislocatedsequenceinenergyconsumptionwasunavoidableintheaftermathoftheoilpriceincreasesinthe1970s.ThishadanadverseeffectonGNPsincemorethan53.4%ofthecountry'sexportproceedswenttooilimportsin1987,tothedetrimentofotherequallyvitalsectorsoftheeconomy(Davidson,1992).Theinstantaneouscausaldirectionbe-tweenenergyandGDPandviceversaindicatesthesensitivityofeconomicactivitiestoenergyconsumption,asfullutilizationofeconomiccapacitybecamedependentonfuelavailability.TheF-statistics,asweexplainedinthecaseoftheGrangertest,arenotusuallyrequiredhereasatestofsignificancebutrelyonthestandarderrorsoftheregressions.However,weusedthemtotestthesignificanceofcurrentvalueofYwhichweincludedintheequation.Wecanobservethattheyaresignificantatthe5%level.TheGrangertestresultsforNigeriashowninTabl