曼昆 宏觀經(jīng)濟(jì)經(jīng)濟(jì)學(xué)第九版 英文原版答案

1、AnswerstoTextbookQuestionsProblemsCHAPTER9EconomicGrowthII:TechnologyEmpiricsPolicyQuestionsfReview1.IntheSolowmodelwefindthatonlytechnologicalprogresscanaffectthesteadystaterateofgrowthinincomeperwker.Growthinthecapital

2、stock(throughhighsaving)hasnoeffectonthesteadystategrowthrateofincomeperwkerneitherdoespopulationgrowth.Buttechnologicalprogresscanleadtosustainedgrowth.2.InthesteadystateoutputperpersonintheSolowmodelgrowsattherateoftec

3、hnologicalprogressg.Capitalperpersonalsogrowsatrateg.Notethatthisimpliesthatoutputcapitalpereffectivewkerareconstantinsteadystate.IntheU.S.dataoutputcapitalperwkerhavebothgrownatabout2percentperyearfthepasthalfcentury.3.

4、TodecidewhetheraneconomyhasmelesscapitalthantheGoldenRuleweneedtocomparethemarginalproductofcapitalofdepreciation(MPK–δ)withthegrowthrateoftotaloutput(ng).ThegrowthrateofGDPisreadilyavailable.Estimatingthemarginalproduct

5、ofcapitalrequiresalittlemewkbutasshowninthetextcanbebackedoutofavailabledataonthecapitalstockrelativetoGDPthetotalamountofdepreciationrelativetoGDPcapital’sshareinGDP.4.Economicpolicycaninfluencethesavingratebyeitherincr

6、easingpublicsavingprovidingincentivestostimulateprivatesaving.Publicsavingisthedifferencebetweengovernmentrevenuegovernmentspending.Ifspendingexceedsrevenuethegovernmentrunsabudgetdeficitwhichisnegativesaving.Policiestha

7、tdecreasethedeficit(suchasreductionsingovernmentpurchasesincreasesintaxes)increasepublicsavingwhereaspoliciesthatincreasethedeficitdecreasesaving.Avarietyofgovernmentpoliciesaffectprivatesaving.Thedecisionbyahouseholdtos

8、avemaydependontherateofreturnthegreaterthereturntosavingthemeattractivesavingbecomes.Taxincentivessuchastaxexemptretirementaccountsfindividualsinvestmenttaxcreditsfcpationsincreasetherateofreturnencourageprivatesaving.5.

9、Thelegalsystemisanexampleofaninstitutionaldifferencebetweencountriesthatmightexplaindifferencesinincomeperperson.CountriesthathaveadoptedtheEnglishstylecommonlawsystemtendtohavebetterdevelopedcapitalmarketsthisleadstomer

10、apidgrowthbecauseitiseasierfbusinessestoobtainfinancing.Thequalityofgovernmentisalsoimptant.Countrieswithmegovernmentcruptiontendtohavelowerlevelsofincomeperperson.6.Endogenousgrowththeiesattempttoexplaintherateoftechnol

11、ogicalprogressbyexplainingthedecisionsthatdeterminethecreationofknowledgethroughresearchdevelopment.BycontrasttheSolowmodelsimplytookthisrateasexogenous.IntheSolowmodelthesavingrateaffectsgrowthtemparilybutdiminishingret

12、urnstocapitaleventuallyfcetheeconomytoapproachasteadystateinwhichgrowthdependsonlyonexogenoustechnologicalprogress.Bycontrastmanyendogenousgrowthmodelsinessenceassumethatthereareconstant(ratherthandiminishing)returnstoca

13、pitalinterpretedtoincludeknowledge.Hencechangesinthesavingratecanleadtopersistentgrowth.ProblemsApplications1.a.IntheSolowmodelwithtechnologicalprogressyisdefinedasoutputpereffectivewkerkisdefinedascapitalpereffectivewke

14、r.ThenumberofeffectivewkersisdefinedasL?E(LE)whereListhenumberofwkersEmeasurestheefficiencyofeachwker.Tofindoutputpereffectivewkerydividetotaloutputbythenumberofeffectivewkers:YLE?K13(LE)23LEYLE?K13L23E23LEYLE?K13L13E13Y

15、LE?KLE??????13y?k13Tosolvefcapitalpereffectivewkerwestartwiththesteadystatecondition:Δk=sf(k)–(δng)k=0.Nowsubstituteinthegivenparametervaluessolvefcapitalpereffectivewker(k):Substitutethevaluefkbackintothepereffectivewke

16、rproductionfunctiontofindoutputpereffectivewkerisequalto2.ThemarginalproductofcapitalisgivenbySubstitutethevaluefcapitalpereffectivewkertofindthemarginalproductofcapitalisequalto112.c.AccdingtotheGoldenRulethemarginalpro

17、ductofcapitalisequalto(δng)0.06.Inthecurrentsteadystatethemarginalproductofcapitalisequalto1120.083.TherefewehavelesscapitalpereffectivewkerincomparisontotheGoldenRule.Asthelevelofcapitalpereffectivewkerrisesthemarginalp

18、roductofcapitalwillfalluntilitisequalto0.06.Toincreasecapitalpereffectivewkertheremustbeanincreaseinthesavingrate.d.DuringthetransitiontotheGoldenRulesteadystatethegrowthrateofoutputperwkerwillincrease.Inthesteadystateou

19、tputperwkergrowsatrateg.Theincreaseinthesavingratewillincreaseoutputpereffectivewkerthiswillincreaseoutputpereffectivewker.Inthenewsteadystateoutputpereffectivewkerisconstantatanewhigherleveloutputperwkerisgrowingatrateg

20、.Duringthetransitionthegrowthrateofoutputperwkerjumpsupthentransitionsbackdowntorateg.3.TosolvethisproblemitisusefultoestablishwhatweknowabouttheU.S.economy:?ACobb–Douglasproductionfunctionhasthefmy=kαwhereαiscapital’ssh

21、areofincome.Thequestiontellsusthatα=0.3soweknowthattheproductionfunctionisy=k0.3.?Inthesteadystateweknowthatthegrowthrateofoutputequals3percentsoweknowthat(ng)=0.03.?Thedepreciationrateδ=0.04.?Thecapital–outputratioKY=2.