克鲁格曼国际经济学答案解析

WORD格式-可编辑Chapter3In1986,thepriceofoilonworldmarketsdroppedsharply.SincetheUnitedStatesisanoil-importingcountry,thiswaswidelyregardedasgoodfortheU.S.economy.YetinTexasandLouisiana1986wasayearofeconomicdecline.Why?ItcandeducethatTexasandLouisianaareoil-producingstatesofUnitedStates.Sowhenthepriceofoilonworldmarketsdeclined,therealwageofthisindustryfellintermsofothergoods.Thismightbethereasonofeconomicdeclinethesetwostatesin1986.2。Aneconomycanproducegood1usinglaborandcapitalandgood2usinglaborandland.Thetotalsupplyoflaboris100units.Giventhesupplyofcapital,theoutputsofthetwogoodsdependsonlaborinputasfollows:Toanalyzetheeconomy’sproductionpossibilityfrontier,considerhowoutputmixchangesaslaborisshiftedbetweenthetwosectors.Graphtheproductionfunctionsforgood1andgood2.QQ1 1

(K,L1 1

Q Q2

(K,L)2 2Output1009080706050403020100

ProductionFunctionforGood173.680.76657.548.638.125.1

87.4

10093.90 10 20

40 50 60 70 80 90 100LaborInputforGood1Output1009080706050

ProductionFunctionforGood275.881.569.361.852.5

86.7

91.4

95.510040 39.830 --整理分享20100 00 10 20 30 40 50 60 70 80 90 100WORD格式-可编辑Graphtheproductionpossibilityfrontier.Whyisitcurved?QQ2 2

(K,L Q)22 2)2100L2

PPFQ1100 L1 Q1

Q(K,L)1 1 1ThePPFiscurvedduetodecliningmarginalproductoflaborineachgood.Thetotallaborsupplyisfixed.SoasL1

rises,MPL1

falls;correspondingly,asLfalls,MPL2

rises.SoPPgetssteeperaswemovedownittotheright.Themarginalproductoflaborcurvescorrespondingtotheproductionfunctionsinproblem2areasfollows:Supposethatthepriceofgood2relativetothatofgood2.Determinegraphicallythewagerateandtheallocationoflaborbetweenthetwosectors.Withtheassumptionthatlaborisfreelymobilebetweensectors,itmovefromthelow-wagesectortothehigh-wagesectoruntilwagesareequalized.Soinequilibrium,thewagerateisequaltothevalueoflabor’smarginalproduct.MPLP1 1

MPLP2

P/P22 1专业知识--整理分享WORD格式-可编辑Theabscissaofpointofintersectionillustratedaboveshouldbebetween(20,30).Sinceweonlyhavetofindouttheapproximateanswer,linearfunctioncouldbeemployed.Thelaborallocationbetweenthesectorsisapproximately=27andL=73.1 2Thewagerateisapproximately0.98.Usingthegraphdrawnforproblem2,determinetheoutputofeachsector.Then confirm graphicallythat the slop of the production possibilityfrontieratthatpointequalstherelativeprice.Q Q2 2

(K,L) Q2 2 2

slope12100 PPFQLQ2 1100L1

Q Q1 1

(K,L)1 1TherelativepriceisP/P=2andwehavegottheapproximatelaborallocation,2 1sowecanemploythelinearfunctionagaintocalculatetheapproximateoutputofeachsector:Q=44andQ=90.1 2Supposethattherelativepriceofgood2fallsto1.Repeat(a)and(b).专业知识--整理分享WORD格式-可编辑Therelativedeclineinthepriceofgood2causedlabortobereallocated:laborisdrawnoutofproductionofgood2andentersproductionofgood1(Ｌ=62,L=38).Thisalsoleadstoanoutputadjustment,thatis,production1 2ofgood2fallsto68unitsandproductionofgood1risesto76units.Andthewagerateisapproximatelyequalto0.74.Q Q2 2

(K,L) Q2 2 2

slope12slope1100 PPFQLQ2 1100L1

Q Q1 1

(K,L)1 1Calculatetheeffectsofthepricechangeontheincomeofthespecificfactorsinsectors1and2.WiththerelativepricechangefromP/P=2toP/P=1,thepriceofgood22 1 2 1hasfallenby50percent,whilethepriceofgood1hasstayedthesame.Wageshavefallentoo,butbylessthanthefallinP(wagesfell2approximately25percent).Thus,therealwagerelativetoP2

actuallyriseswhilerealwagerelativetoPfalls.Hence,todeterminethewelfare1consequenceforworkers,theinformationabouttheirconsumptionsharesgood1andgood2isneeded.--整理分享WORD格式WORD格式-可编辑专业知识专业知识--整理分享Inthetextweexaminedtheimpactsofincreasesinthesupplyofcapitalandland.Butwhatifthemobilefactor,labor,increasesinsupply?Analyzethequalitativeeffectsofanincreaseinthesupplyoflaborinthespecificfactorsmodel,holdingthepriceofbothgoodsconstant.Foraneconomyproducingtwogoods,XanY,withlabordemandsreflectedbytheirmarginalrevenueproductcurves,thereisaninitialwageofw1

andaninitiallaborallocationofL=OAandL=OA.Whenthesupplyoflaborx x y yincreases,therightboundaryofthediagramillustratedbelowpushedouttoO’.ThedemandforlaborinsectorYispulledrightwardwiththeboundary.yThenewintersectionofthelabordemandcurvesshowsthatlaborexpandsbothsectors,andthereforeoutputofbothXandYalsoexpand.Therelativeexpansionofoutputisambiguous.Wagespaidtoworkersfall.yyMPL PyyMPL Px xWw1w2A B O Oy yGraphtheeffectontheequilibriumforthenumericalexampleinproblems2and3,givenarelativepriceof1,whenthelaborforceexpandsfrom100to140.Withthelawofdiminishingreturns,thenewproductionpossibilityfrontierismoreconcaveandsteeper(flatter)attheendswhentotallaborsupplyincreases.Lincreaseto90from62andLincreasesto50from38.Wagesdeclinefrom1 20.74to0.60.ThisnewallocationoflaborleadstoanewoutputmixofapproximatelyQ=85andQ=77.1 2QQQ(K,L)2 2 2 2Q2140100PPFL2Q1140100LQQ(K,L)

1 1 1 1 1IntheUnitedStateswherelandischeap,theratiooflandtolaborusedincattlerisingishigherthanthatoflandusedinwheatgrowing.Butinmorecrowdedcountries,wherelandisexpensiveandlaborischeap,itiscommontoraisecowsbyusinglesslandandmorelaborthanAmericansusetogrowwheat.Canwestillsaythatraisingcattleislandintensivecomparedwithfarmingwheat?Whyorwhynot?Thedefinitionofcattlegrowingaslandintensivedependsratiooflandtolaborusedinproduction,notontheratiooflandorlabortooutput.ratiooflandtolaborincattleexceedstheratioinwheatintheUnitedStates,implyingcattleislandintensiveintheUnitedStates.Cattleislandintensiveinothercountriestooiftheratiooflandtolaborincattleproductionexceedstheratioinwheatproductioninthatcountry.ThecomparisonbetweenanothercountryandtheUnitedStatesislessrelevantforansweringthequestion.Supposethatatcurrentfactorpricesclothisproducedusing20hoursoflaborforeachacreofland,andfoodisproducedusingonly5hoursoflaborperacreofland.Supposethattheeconom’stotalresourcesare600hoursoflaborand60acresofland.Usingadiagramdeterminetheallocationofresources.aLC/aTC(LC/QC)/(TC/QC)LCaLF/aTF(LF/QF)/(TF/QF)LF/TF

LC20TC LF5TFWecansolvethisalgebraicallysinceL=LC+LF=600andT=TC+TF=60.ThesolutionisLC=400,TC=20,LF=200andTF=40.LF FoodLandTC TFCloth

Labor LCNowsupposethatthelaborsupplyincreasefirstto800,then1000,then1200hours.UsingadiagramlikeFigure4-6,traceoutthechangingallocationofresources.L800:TC33.33,LC666.67,TF26.67,LF133.33L1000:TC46.67,LC933.33,TF13.33,LF66.67L1200:TC60,LC1200,TF0,LF0.(completespecialization).FoodLand01200 01000 0800 Clothl l lLaborWhatwouldhappenifthelaborsupplyweretoincreaseevenfurther?Atconstantfactorprices,somelaborwouldbeunused,sofactorpriceshavetochange,ortherewouldbeunemployment.“Theworlspoorestcountriescannotfindanythingtoexport.Thereisnoresourcethatisabundant—certainlynotcapitalorland,andinsmallpoornationsnotevenlaborisabundant.”Discuss.Thegainsfromtradedependoncomparativeratherthanabsoluteadvantage.topoorcountries,whatmattersisnottheabsoluteabundanceoffactors,theirrelativeabundance.Poorcountrieshaveanabundanceoflaborrelativetocapitalwhencomparedtomoredevelopedcountries.TheU.S.labormovement—whichmostlyrepresentsblue-collarworkersratherthanprofessionalsandhighlyeducatedworkers—hastraditionallyfavoredlimitsonimportsformless-affluentcountries.Isthisashortsightedpolicyofarationaloneinviewoftheinterestsofunionmembers?Howdoestheanswerdependonthemodeloftrade?IntheRicardo’smodel,laborgainsfromtradethroughanincreaseinitspurchasingpower.Thisresultdoesnotsupportlaboruniondemandsforlimitsonimportsfromlessaffluentcountries.IntheImmobileFactorsmodellabormaygainorlosefromtrade.Purchasingpowerintermsofonegoodwillrise,butintermsoftheothergooditwilldecline.TheHeckscher-Ohlinmodeldirectlydiscussesdistributionbyconsideringeffectsoftradeontheownersoffactorsofproduction.Inthecontextofthismodel,unskilledU.S.laborlosesfromtradesincethisgrouprepresentsrelativelyscarcefactorsinthiscountry.TheresultsfromtheHeckscher-Ohlinmodelsupportlaboruniondemandsforimportlimits.ThereissubstantialinequalityofwagelevelsbetweenregionswithintheUnitedStates.Forexample,wagesofmanufacturingworkersinequivalentjobsareabout20percentlowerintheSoutheastthantheyareintheFarWest.Whichoftheexplanationsoffailureoffactorpriceequalizationmightaccountforthis?HowisthiscasedifferentfromthedivergenceofwagesbetweentheUnitedStatesandMexico(whichisgeographicallyclosertoboththeU.S.SoutheastandtheFarWestthantheSoutheastandFarWestaretoeachother)?Whenweemployfactorpriceequalization,weshouldpayattentiontoitsconditions:bothcountries/regionsproducebothgoods;bothcountrieshavethesametechnologyofproduction,andtheabsenceofbarrierstotrade.InequalityofwagelevelsbetweenregionswithintheUnitedStatesmaycausedbysomeallofthesereasons.Actually,thebarrierstotradealwaysexistintherealworldduetotransportationcosts.AndthetradebetweenU.S.andMexico,bycontrast,subjecttolegallimits;togetherwithculturaldifferencesthatinhibitflowoftechnology,thismayexplainwhythedifferenceinwageratesissomuchlarger.Explainwhythe LeontiefparadoxandthemorerecentBowen,Leamer,andSveikauskasresultsreportedinthetextcontradictthefactor-proportionstheory.Thefactorproportionstheorystatesthatcountriesexportthosegoodswhoseproductionisintensiveinfactorswithwhichtheyareabundantlyendowed.OnewouldexpecttheUnitedStates,whichhasahighcapital/laborratiorelativetotherestoftheworld,toexportcapital-intensivegoodsiftheHeckscher-Ohlintheoryholds.LeontieffoundthattheUnitedStatesexportedlabor-intensivegoods.Bowen,LeamerandSveikauskasfoundthatthecorrelationbetweenfactorendowment