能源效率与地方宏观反弹效应：理论与卢旺达的实验证据

AnicetMunyehirwe,JörgAnkel-Peters,MaximilianeSievert,ErwinBulte,andNathanFiala Abstract Energyefficiencyisakeycomponentofclimatepolicy.Thereboundeffect,namelytheincreasesindemandinresponsetoefficiency-inducedpricereductions,potentiallynullifiessomeoftheenergysavingsfromenergy-efficiencyimprovements.Thispaperexaminesmacroreboundeffectsfollowingtheintroductionofenergy-efficientbiomasscookstoves(EEBCs)inruralSub-SaharanAfrica.Itpresentsamodelofbiomasssupplyanddemand,andempiricallyevaluatesagovernmentpilotprojectinRwandathatrandomlysubsidizedEEBCsatthevillagelevel,leadingtoexogenousvariationinadoptionrates.Thepaperexploresconsumptionspilloverstononadoptersthroughpricereactionsonlocalvillagemarkets,referredtoasthe“localmacroreboundeffect.”Thetheoreticalmodelandempiricalresultsshowthatequilibriumresponseeffectscantakedifferentforms,dependingonthelocalcontext.Thepaperidentifiesconditionsthatdeterminetheshapeandsizeofsucheffects.Public Disclosure Authorized JELclassification:R13,D12,O13,Q28 Keywords:energyefficiency,macroreboundeffect,technologyadoption,improvedcooking 1.IntroductionPublic Disclosure Authorized Increasingenergyefficiencyiscrucialtoreachglobalclimategoalsandisatthecoreofthesustainabledevelopmentagenda(UN2015).Policiestoincentivizeenergyefficiencyarecommonlyseenaswin-winstrategiesbecausetheyfosterprivatelyprofitableinvestmentsandgenerateenvironmentalbenefits.A Orderingofauthorsisrandomized.AnicetMunyehirweisthefounderandCEOofIB&CRwanda;hisemailaddressismunyehirwe@gmail.com.JörgAnkel-Petersisco-headingtheresearchdepartmentClimateandDevelopmentPolicyatRWI– LeibnizInstituteforEconomicResearchandisaprofessorattheUniversityofPassau;hisemailaddressispeters@rwi-essen.de.MaximilianeSievert(correspondingauthor)isco-headingtheresearchdepartmentClimateandDevelopmentPolicyatRWI—LeibnizInstituteforEconomicResearch;heremailaddressissievert@rwi-essen.de.ErwinBulteisaprofessoratWageningenUniversity;hisemailaddressiserwin.bulte@wur.nl.NathanFialaisaprofessorattheUniversityofConnecticut;hisemailaddressisnathan.fiala@uconn.edu.TheauthorsthankparticipantsattheGermanDevelopmentEconomicsConfer-ence(Hohenheim),theEfDAnnualMeeting(Bogota),EAERE(ManchesterandRimini),theFrankfurtSchoolofFinance&Management,andtheUniversityofHeidelbergforvaluablecomments.ThanksalsogotoGuntherBensch,MichaelGrimm,FarazUsmani,andMadelineWerthschulteforfeedbackandcomments.TheauthorsthankRamlahAbbasforexcellentre-searchassistance.TheauthorsalsothankREG/EDCLandtheMinistryofInfrastructureofRwandafortheircooperationinimplementingthestudy.Thispaper’smainhypotheseswerepre-specifiedinapre-analysisplan(PAP)attheAEARCTRegistry(AEARCTR-0002794),butthetheoreticalmodelwasdevelopedexpost.Duetopowerproblems,thestudydeviatesquitesubstantiallyfromtheoriginalPAP.Thepaperdiscussesthisissuetransparently.AsupplementaryonlineappendixisavailablewiththisarticleatTheWorldBankEconomicReviewwebsite.Public Disclosure Authorized broadlyheldviewisthatenergyefficiencygapsofferlow-hangingfruitforabatingcarbonemissions(Gerarden,Newell,andStavins2017).However,empirical assessmentssuggest thatclosing energyeffi-ciencygapsyieldssmallergainsthanhypothesized(AllcottandGreenstone2012;Fowlie,Greenstone,andWolfram2018).The rebound effect provides one possible explanation:improved energy efficiencyreducestherelativepriceofenergy,whichtriggersadditionalconsumption––nullifyingsomeoftheearliersavings(Gillingham,Rapson,andWagner2016).Theliteraturedistinguishesbetweenmicroandmacrorebounds.Theformeroccurifindividualsin- creaseenergyconsumptionfollowinganincreaseinefficiency,whilemacroreboundsoccurduetopricechangesinthegeneralequilibrium(ChanandGillingham2015).Themicro-reboundhasbeenstudiedwidely(Davis2008;Davis,Fuchs,andGertler2014;Frondel,Peters,andVance2008;Gillingham2014).Macroreboundeffectsaremuchmoredifficulttostudy,andidentifyingcausationatthecountryorgloballevelispracticallyimpossible(Gillingham,Rapson,andWagner2016).This paperstudies a macrore-boundataloweraggregationlevel:Itlooksatlocalvillage-levelbiomassmarketsinSub-SaharanAfrica(SSA)andstudiespricechangesanddemandresponsesaftertheintroductionofanewenergy-efficienttechnology.Thiseffectisreferredtoasthe“localmacroreboundeffect” (LMRE).Theenergyefficiencyliteraturehithertohasmostlyfocusedonhigh-incomecountries,whileenergy demandisrisingmostsharplyinSSAandAsia(FowlieandMeeks2021;IEA2022).ThemostimportantenergysourceinSSAisbiomass—mostlyfirewoodandcharcoalforcooking—accountingformorethan75percentoftotalprimaryenergydemand(excludingSouthAfrica,IEA2019).Morethan3billionpeopleusebiomassforcooking,ofwhom900millionliveinSSA.Itisextractedunsustainablyfromforestsinmanysettings,andbiomassusageemitsconsiderableamountsofcarbonintheatmosphere(Bailisetal.2015).Woodfuel-inducedemissionsinSSAarecomparabletothetotalemissionsofalarge,industrializedcountrysuchasGermanyand,duetopopulationgrowthandurbanization,areprojectedtoriseinthefuture(Bensch,Jeuland,andPeters2021).To reduce pressure on forests,promoting thediffusionofenergy-efficientbiomassc