宏觀經(jīng)濟(jì)學(xué)原理答案

宏觀經(jīng)濟(jì)學(xué)原理（第六版）梁小民改編

Unit4Application:InternationalTrade

1.Thesupplycurveshowsthequantityofagoodsuppliedbysellers,andthe

demandcurveshowsthequantityofagooddemandedbybuyers.Whenthe

domesticquantitysuppliedisgreaterthanthedomesticquantitydemanded,a

countrysellsthegoodtoothercountries,thusthecountrybecomeanexporterofa

good,conversely,thecountrybecomeanimporterofagood.

2.P57圖

3.Tariffisataxongoodsproducedabroadandsolddomestically.

Theeconomiceffectsoftariff:Thetariffraisesthedomesticprice,domesticsellers

arebetteroff,anddomesticbuyersareworseoff.Inaddition,thegovernment

raisesrevenue.First,whenthetariffraisesthedomesticpriceabovetheworldprice,

itencouragesdomesticproducerstoincreaseproduction.Second,whenthetariff

raisesthepricethatdomesticgoodsconsumershavetopay,itencouragesthemto

reduceconsumptionofgoods.

4.Therearevariousargumentsforrestrictingtrade:protectingjobs,defending

nationalsecurity,helpinginfantindustries,preventingunfaircompetition,and

respondingtoforeigntraderestrictions.Althoughsomeoftheseargumentshave

somemeritinsomecases,economistsbelievethatfreetradeisusuallythebetter

policy.

Unit5MeasuringaNationsIncome

1.TheproductionofaluxurycarcontributesmoretoGDPthantheproductionof

aneconomycar.Becausemarketpricesmeasuretheamountpeoplearewillirgto

payfordifferentgoods,theyreflectthevalueofthosegoods.Theluxurycarhasa

highermarketvalue.

2.ThecontributiontoGDPis3$,themarketvalueofthebread,whichisthefinal

goodthatissold.

3.ThefourcomponentsofGDPareconsumption,suchasthepurchaseofamusic

CD;investment,suchasthepurchaseofacomputerbyabusiness;government

purchases,suchasanorderformilitaryaircraft;andnetexports,suchasthesaleof

AmericanwheattoRussian.

4.EconomistsuserealGDPratherthannominalGDPtogaugeeconomicwell-

beingbecauserealGDPisnotaffectedbychangesinprices,soitreflectsonly

changesintheamountsbeingproduced.IfnominalGDPrises,youdonotknowif

thatisbecauseofincreasedproductionorhigherprices.

Unit6MeasuringtheCostofLiving

1.A10percentincreaseinthepriceofchickenhasagreatereffectontheconsumer

priceindexthana10percentincreaseinthepriceofcaviarbecausechickenisa

biggerpartoftheaverageconsumer,smarketbasket.

2.Thethreeproblemsintheconsumerpriceindexasameasureofthecostofliving

are:(1)substitutionbias,whicharisesbecausepeoplesubstitutetowardgoodsthat

havebecomerelativelylessexpensive;(2)theintroductionofnewgoods,whichare

notreflectedquicklyintheCPI;(3)unmeasuredqualitychange

3.IfthepriceofaNavysubmarinerises,thereisnoeffectontheconsumerprice

index,sinceNavysubmarinesarenotconsumergoods.ButtheGDPpriceindexis

affected,sinceNavysubmarinesareincludedinGDPasapartofgovernment

purchases.

4.Sincetheoverallpriceleveldoubled,butthepriceofthecandybarrosesixfold,

therealprice(thepriceadjustedforinflation)ofthecandybartripled.

5.Thenominalinterestrateistheinterestratepaidonaloanindollarterms.

Therealinterestrateistheinterestratecorrectedfortheeffectsofinflation.

Therealinterestrateisthenominalinterestrateminustherateofinflation.

Unit7ProductionandGrowth

1.Thefourdeterminantsofproductivityare:(1)physicalcapital,whichisthestock

ofequipmentandstructuresthatareusedtoproducegoodsandservices;(2)

humancapital,whichconsistsoftheknowledgeandskillsthatworkersacquire

througheducation,training,andexperience;(3)naturalresources,whichareinputs

intotheproductionofgoodsandservicesthatareprovidedbynature;and

(4)technologicalknowledge,whichissociety*sunderstandingofthebestwaysto

producegoodsandservices.

2.Highersavingmeansfewerresourcesaredevotedtoconsumptionandmoreto

producingcapitalgoods.Theriseinthecapitalstockleadstorisingproductivity

Publicsavingistheamountoftaxrevenuethatthegovernmenthasleftpayingfor

itsspending.Thethreevariablesarerelatedbecausenationalsavingequalsprivate

savingpluspublicsaving.

3.Investmentreferstothepurchaseofnewcapital,suchasequipmentorbuildings.

Itisequaltonationalsaving.

4.Achangeintaxcodethatmightincreaseprivatesavingistheintroductionofa

consumptiontaxtoreplacetheincometax.Sinceaconsumptiontaxwouldnottax

thereturnssaving,itwouldincreasethesupplyofloanablefunds,thuslowering

interestratesandincreasinginvestment.

5.Agovernmentbudgetdeficitariseswhengovernmentspendsmorethanit

receivesintaxrevenue.Sinceagovernmentbudgetdeficitreducesnationalsaving,

itraisesinterestrates,reducesprivateinvestment,andthusreduceseconomic

growth.

Unit9TheBasicToolsofFinance

1.Purchasinginsuranceallowsanindividualtoreducethelevelofriskhefaces.Two

problemsthatimpedetheinsuranceindustryfromworkingcorrectlyareadverse

selectionandmoralhazard.Adverseselectionoccursbecauseahigh-riskpersonis

morelikelytoapplyforinsurancethanalow-riskpersonis.Moralhazardoccurs

becausepeoplehavelessincentivetobecarefulabouttheirriskybehaviorafter

theypurchaseinsurance.

2.Astockanalystwillconsiderthefutureprofitabilityofafirmwhendetermining

thevalueofthestock.

3.Theefficientmarketshypothesissuggeststhatstockpricesreflectallavaiable

information.Thismeansthatwecannotusecurrentinformationtopredictfuture

changesinstockprices.Onepieceofevidencethatsupportsthistheoryisthefact

thatmanyindexfundsoutperformmutualfundsthatareactivelymanagedbya

professionalportfoliomanager.

Unit10Unemployment

1.(l)Frictionalunemplotmentisinevtiablebecausetheeconomyisalways

changing.Somefirmsareshringkingwhileothersareexpanding.Someregionsare

experiencingfastergrowththanotherregions.Transitionsofworkersbetween

firmsandbetweenregionsareaccompaniedbytemporaryunemployment.

(2)Thegovernmentcouldhelptoreducetheamountoffritionalunemploymentby

publicpoliciesthatprovideinformationaboutjobvacanciesinordertomatch

workersandjobsmorequickly,andthroughpublictrainingprogramsthathelp

easethetransitionofworkersfromdecliningtoexpandingindustriesandhelp

disadvantagedgroupsescapepoverty.

2.Minimum-wagelawsareabetterexplanationforunemploymentamong

teenagersthanamongcollegegraduates.Teenagershavefewerjob-relatedskills

thancollegegraduatesdo,sotheirwagesarelowenoughtobeaffectedbythe

minimumwage.Collegegraduates1wagesgenerallyexceedtheminimumwage.

3.Unionsmayaffectthenaturalrateofunemploymentviatheeffectoninsiders

andoutsiders.Sinceunionsraisethewageabovetheequilibriumlevel,thequantity

oflabordemandeddeclineswhilethequantitysuppliedoflaborrises,sothereis

unemployment.Insidersarethosewhokeeptheirjobs.Outsiders,workerswho

becomeunemployed,havetwochoices:eithergetajobinafirmthatisnot

unionizedorremainunemployedandwaitforajobtoopenupintheuionsector.

Asaresult,thenaturalrateofunemploymentishigherthanitwouldbewithout

unions.

4.Advocatesofunionsclaimthatunionsaregoodfortheeconomybecausethey

areanantidotetothemarketpowerofthefirmsthathireworkersandtheyare

importantforhelpingfirmsrespondeffeicientlytoworkers*concerns.

5.Fourreasonswhyafirm/sprofitsmightincreasewhenitraiseswagesare:(1)

betterpaidworkersarehealthierandmoreproductive;(2)workerturnoveris

reduced;(3)workereffortisincreased;and(4)thefirmcanattracthigherquality

workers.

Unit11TheMonetarySystem

1.Moneyisdifferentfromotherassetsintheeconomybecauseitismostliquid

assetavailable.Otherassetsvarywidelyintheirliquidity.

2.Commoditymoneyismoneywithintrinsicvalue,likegold,whichcanbeusedfor

purposesotherthanasamediumofexchange.Fiatmoneywithoutintrinsicvalue,it

hasnovalueotherthanitsuseasamediumofexchange.Oureconomytodayuses

fiatmoney.

3.Ifthefedwantstoincreasethesupplyofmoneywithopen-marketoperation,it

purchasesU.Sgovernmentbondsfromthepublicontheopenmarket.The

purchaseincreasesthenumberofdollarsinthehandofthepublic,thusraisingthe

moneysupply.

4.Reserverequirementsareregulationsontheminimumamountofreservesthat

banksmustholdagainstdeposits.Anincreaseinreserverequirementraisesthe

ratio,lowersthemoneymultiplier,anddecreasesthemoneysupply.

5.ThediscountrateistheinterestrateloansthattheFederalReservemakesto

banks.IftheFedraisesthediscountrate,fewerbankswillborrowfromtheFed,so

banks'reserveswillbelower;andthusthemoneysupplywillbelower.

6.TheFedcannotcontrolthemoneysupplyperfectlybecause:(1)theFeddoesnot

controltheamountofmoneythathouseholdschoosetoholdasdepositsinbanks,

and(2)theFeddoesnotcontroltheamountthatbankerschoosetolend.The

actionsofhouseholdsandbanksaffectthemoneysupplyinwaystheFedcannot

perfectlycontrolorpredict.

Unit12MoneyGrowthandInflation

1.Accordingtothequantitytheoryofmoney,anincreaseinthequantityofmoney

causesaproportionalincreaseinthepricelevel.

2.Nominalvariablesarethosemeasuredinmonetaryunits,whilerealvariablesare

thosemeasuredinphysicalunits.Examplesofnominalvariablesincludethe

pricesofgoods,wages,andthedollarvalueofGDRExamplesofrealvariables

includerelativeprices(thepriceofonegoodintermsofanthor),realwages,and

realGDRAccordingtothepricinpleofmonetaryneutrality,onlynominalvariables

areaffectedbychangesinthequantityofmoney.

3.Inflationislikeataxbecauseeveryonewhoholdsmoneylosespurchasingpower.

Inahyperinflation,thegovernmentincreasesthemoneysupplyrapidly,which

leadstoahighrateofinflation.Thusthegovernmentusestheinflationtax,instead

oftaxesonincome,tofinaceitsspending.

4.AccordingtotheFishereffect,anincreaseintheinflationrateraisesthenominal

interestratebythesarreamountthattheinflationrateincreases,withnoeffecton

therealinterestrate.

5.Ifinflationislessthanexpected,creditorsbenefitanddebtorslose.Creditors

receivedollarpaymentsfromdebtorsthathaveahigherrealvaluethanwas

expected.

Unit13Open-EconomyMacroeconomicsBasicConcepts

1.Thenetexporysofacountryarethevalueofitsexportsminusthevalueofits

imports.

Netcapitaloutflowreferstothepurchaseofforeignassetsbydomesticresidents

minusthepurchaseofdomesticassetsbyforeigners.

Netexportsareequaltonetcapitaloutflowbyanaccountingidentity,since

exportsfromonecountrytoanthorarematchedbypaymentsofsomeassetfrom

thesecondcountrytothefirst.

2.Savingequalsdomesticinvestmentplusnetcapitaloutflow,sinceanydollar

savedcanbeusedtofinaceaccumulationofdomesticcapitaloritcanbeusedto

fiancethepurchaseofcapitalabroad.

3.Ifadollarcanbuy100yen,thenominalexchangerateis100yenperdollar.The

realexchangerateequalsthenominalexchangeratetimesthedomesticprice

dividedbytheforeignprice,whichequals100yenperdollartimes$10,000per

Ameicancardividedby500,000yenperJapanesecar,whichequals2Japanesecars

perAmeicancar.

4.Theeconomiclogicbehinddthetheoryofpurchasing-powerparityisthata

goodmustsellforthesamepriceinalllocations.Otherwise,peoplewouldprofit

byengainginarbitrage.

5.IftheFedstartedprintinglargequantitiesofU.S.dollars,theU.Spricelevel

wouldincrease,andadollarwouldbuyfewerJapaneseyen.

Unit14AMacroeconomicTheoryoftheOpenEconomy

1.Thesupplyofloanablefundscomesfromnatinalsaving,thedemandfor

loanablefundscomesfromdomesticinvestmentandnetcapitaloutflow.The

supplyofdoallarsinthemarketforforeignexchangecomesfromnetcapital

outflow,thedemandfordollarsinthemarketforforeignexchangecomesfromnet

ecperts.Thelinebetweenthetwomartketsisnetcapitaloutflow.

2.Governmentbudgetdeficitsandtradedeficitsaresometimescalledthetwin

deficitsbecauseagovernmemtbudgetdeficitoftenleadstotradedeficitThe

dovernmentbudgetdeficitleadstoreducednationalsaving,causingtheinterest

rateincrease,thusreducingnetcapitaloutflow,whichinreducesnetexports.

3.IfaunionoftextileworkersencouragespeopletpbuyonlyAerican-made

clothes,importswouldbereduced,sonetexportswouldincreaseforanygivenreal

exchangerate.Thiswouldcausethedemandcurveinthemarketforforeign

exchangetoshifttotheright,asshowninFigure2.Theresultisriseinthereal

exchangerate,butnoeffctonthetradebalance.Thetextileindustrywouldimport

less,butotherindustries,suchastheautoindustry.Wouldimportmorebecauseof

thehigherrealexchangerate.

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QuantityofDollars

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4.Capitalflightisalargeandsuddenmovementoffundsoutofacountry.Capital

flightcausetheinterestratetoincreaseandtheexchangeratetodepreciate.

Unit15AggregateDemandandAggregateSupply

1.Threeaggregate-demandcurveisdownwardslopingbecause:(1)adecreasein

thepricelevelmakesconsumersfeelwealthier;whichinturnencouragesthemto

spendmore,sothereisalargerquantityofgoodsandservicesdemanded;[2)a

lowerpricelevelreducestheinterestrate,enouraginggreaterspendingon

investment,sothereisalargerquantityofgoodsandservicesdemanded;(3)afall

intheU.S.pricelevelcausesU.S.interestratestofall,sotherealexchangerate

depreciates,stimulatingU.S.netexports,sothereisalargerquantityofgoodsand

servicesdemande.

2.Thelong-runaggregatesupplycurveisverticalbecauseinthelongrun,an

economy*ssupplyofgoodsandservicesdependsonitssuppliesofcapital,labor,

andnaturalresourcesandontheavailableproductiontechnologyusedtoturn

theseresourcesintogoodsandservices.Thepriceleveldoesnotaffectthese

long-rundererminantsofrealGDR

3.Theaggregated-demandcurvemightshifttotheleftwhensomething(other

thanariseinthepricelevel)causesareductioninconsumptionspending(suchasa

desireforincreasedsaving),areductionininvestmentspending(suchasincreased

taxesonthereturnstoinvestment),decreasedgovernmentspending(suchasa

cutbackindefensespending),orreducednetexports(suchaswhenforeign

economicsgointorecession,soourexportsfall.)

Figure4tracesthroughthestepsofsuchashiftinaggregatedemand.The

economybeginsinequilibrium,withshort-runaggregatesupply,ASi,intersecting

aggregatedemand,ADi,atpointA.Whentheaggregate-demandcurveshiftsto

thelefttoAD2,theeconomymovesfrompointAtopointB,reducingtheprice

levelandthequantityofoutput.Overtime,peopleadjusttheirperceptions,wages,

andprices,shiftingtheshort-runaggregate-supplycurvedowntoAS2,and

movingtheeconomyfrompointBtopointC,whichisbackonthelong-run

aggregatesupplycurveandhasalowerpricelevel.

Figure4

4.Theaggregate-supplycurvemightshifttotheleftbecauseofadeclineinthe

economy,scapitalstock,laborsupply,orproductivity,oranincreaseinthenatural

rateofunemployment,allofwhichshiftboththelong-runandshort-runaggregate

supplycurvestotheleft.Anincreaseintheexpectedpricelevelshiftsjustthe

short-runaggregate-supplycurve(notthelong-runaggregate-supplycurve)tothe

left.

Figures5tracesthroughtheeffectsofsuchashiftTheeconomystartsin

equilibriumatpointA.Theaggregate-supplycurvethenshiftstotheleftfromASi

toAS2.ThenewequilibriumisatpointB,theintersectionofaggregate-demand

curveandAS2.Astimegoeson;theeconomyreturnstolong-runequilibriumat

pointA,astheshort-runaggregatesupplycurveshiftsbacktoitsoriginalposition.

Long-run

Aggregate

Supply

Aggregate

Demand

QuantityofOutput

Unit16TheInfluenceofMonetaryandFiscalPolicyon

AggregateDemand

1.ThetheoryofliquiditypreferenceisKeynes'stheoryofhowtheinterstrateis

determined.Accordingtothethoery,theaggregate-demandcurveslopes

downwardbecause:(1)ahigherpricelevelraisesmoneydemand;(2)higher

moneydemandleadstohigherinterestrate;and(3)ahigherinteres