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

1、Chapter9—EconomicGrowthII:TechnologyEmpiricsPolicy71AnswerstoTextbookQuestionsProblemsCHAPTER9EconomicGrowthII:TechnologyEmpiricsPolicyQuestionsfReview1.IntheSolowmodelwefindthatonlytechnologicalprogresscanaffectthestead

2、ystaterateofgrowthinincomeperwker.Growthinthecapitalstock(throughhighsaving)hasnoeffectonthesteadystategrowthrateofincomeperwkerneitherdoespopulationgrowth.Buttechnologicalprogresscanleadtosustainedgrowth.2.Inthesteadyst

3、ateoutputperpersonintheSolowmodelgrowsattherateoftechnologicalprogressg.Capitalperpersonalsogrowsatrateg.Notethatthisimpliesthatoutputcapitalpereffectivewkerareconstantinsteadystate.IntheU.S.dataoutputcapitalperwkerhaveb

4、othgrownatabout2percentperyearfthepasthalfcentury.3.TodecidewhetheraneconomyhasmelesscapitalthantheGoldenRuleweneedtocomparethemarginalproductofcapitalofdepreciation(MPK–δ)withthegrowthrateoftotaloutput(ng).Thegrowthrate

5、ofGDPisreadilyavailable.EstimatingthemarginalproductofcapitalrequiresalittlemewkbutasshowninthetextcanbebackedoutofavailabledataonthecapitalstockrelativetoGDPthetotalamountofdepreciationrelativetoGDPcapital’sshareinGDP.4

6、.Economicpolicycaninfluencethesavingratebyeitherincreasingpublicsavingprovidingincentivestostimulateprivatesaving.Publicsavingisthedifferencebetweengovernmentrevenuegovernmentspending.Ifspendingexceedsrevenuethegovernmen

7、trunsabudgetdeficitwhichisnegativesaving.Policiesthatdecreasethedeficit(suchasreductionsingovernmentpurchasesincreasesintaxes)increasepublicsavingwhereaspoliciesthatincreasethedeficitdecreasesaving.Avarietyofgovernmentpo

8、liciesaffectprivatesaving.Thedecisionbyahouseholdtosavemaydependontherateofreturnthegreaterthereturntosavingthemeattractivesavingbecomes.Taxincentivessuchastaxexemptretirementaccountsfindividualsinvestmenttaxcreditsfcpat

9、ionsincreasetherateofreturnencourageprivatesaving.5.Thelegalsystemisanexampleofaninstitutionaldifferencebetweencountriesthatmightexplaindifferencesinincomeperperson.CountriesthathaveadoptedtheEnglishstylecommonlawsystemt

10、endtohavebetterdevelopedcapitalmarketsthisleadstomerapidgrowthbecauseitiseasierfbusinessestoobtainfinancing.Thequalityofgovernmentisalsoimptant.Countrieswithmegovernmentcruptiontendtohavelowerlevelsofincomeperperson.6.En

11、dogenousgrowththeiesattempttoexplaintherateoftechnologicalprogressbyexplainingthedecisionsthatdeterminethecreationofknowledgethroughresearchdevelopment.BycontrasttheSolowmodelsimplytookthisrateasexogenous.IntheSolowmodel

12、thesavingrateaffectsgrowthtemparilybutdiminishingreturnstocapitaleventuallyfcetheeconomytoapproachasteadystateinwhichgrowthdependsonlyonexogenoustechnologicalprogress.Bycontrastmanyendogenousgrowthmodelsinessenceassumeth

13、atthereareconstant(ratherthandiminishing)returnstocapitalinterpretedtoincludeknowledge.Hencechangesinthesavingratecanleadtopersistentgrowth.ProblemsApplications1.a.IntheSolowmodelwithtechnologicalprogressyisdefinedasoutp

14、utpereffectivewkerkisdefinedascapitalpereffectivewker.ThenumberofeffectivewkersisdefinedasL?E(LE)whereListhenumberofwkersEmeasurestheefficiencyofeachwker.Tofindoutputpereffectivewkerydividetotaloutputbythenumberofeffecti

15、vewkers:Chapter9—EconomicGrowthII:TechnologyEmpiricsPolicy73YLE?K13(LE)23LEYLE?K13L23E23LEYLE?K13L13E13YLE?KLE??????13y?k13Tosolvefcapitalpereffectivewkerwestartwiththesteadystatecondition:Δk=sf(k)–(δng)k=0.Nowsubstitute

16、inthegivenparametervaluessolvefcapitalpereffectivewker(k):0.2413=(0.030.020.01)23=4=8.Substitutethevaluefkbackintothepereffectivewkerproductionfunctiontofindoutputpereffectivewkerisequalto2.Themarginalproductofcapitalisg

17、ivenby=1323.Substitutethevaluefcapitalpereffectivewkertofindthemarginalproductofcapitalisequalto112.c.AccdingtotheGoldenRulethemarginalproductofcapitalisequalto(δng)0.06.Inthecurrentsteadystatethemarginalproductofcapital

18、isequalto1120.083.TherefewehavelesscapitalpereffectivewkerincomparisontotheGoldenRule.Asthelevelofcapitalpereffectivewkerrisesthemarginalproductofcapitalwillfalluntilitisequalto0.06.Toincreasecapitalpereffectivewkerthere

19、mustbeanincreaseinthesavingrate.d.DuringthetransitiontotheGoldenRulesteadystatethegrowthrateofoutputperwkerwillincrease.Inthesteadystateoutputperwkergrowsatrateg.Theincreaseinthesavingratewillincreaseoutputpereffectivewk

20、erthiswillincreaseoutputpereffectivewker.Inthenewsteadystateoutputpereffectivewkerisconstantatanewhigherleveloutputperwkerisgrowingatrateg.Duringthetransitionthegrowthrateofoutputperwkerjumpsupthentransitionsbackdowntora

21、teg.3.TosolvethisproblemitisusefultoestablishwhatweknowabouttheU.S.economy:?ACobb–Douglasproductionfunctionhasthefmy=kαwhereαiscapital’sshareofincome.Thequestiontellsusthatα=0.3soweknowthattheproductionfunctionisy=k0.3.?