上市公司的优缺点

上市公司的优缺点上市公司的优势上市，是指股份有限公司在证券交易所公开发行股票后并公开上市交易。公司上市解决了企业发展所需要的资金，为公司的持续发展获得稳定的长期融资渠道，并借此可以形成良性的资金循环，可以在更广阔的范围内进行融资，从而扩大公司的资本金规模，进而扩大生产，提高盈利空间，并且上市公司股票融资是不用向投资者退还本金的，盈利了就分红，亏了就由股东和公司一起承担亏损。而非上市公司就只能通过借贷的方式来融资，有借就有还，非上市公司因此会承受很大的财务负担，增加企业经营的风险。成为公众公司，可以大大提高知名度（媒体给予一家上市公司的关注远远高于非上市企业），同样可获得名牌效应，积聚无形资产。因为一上市，好多机构投资者就会研究，好多股民也会关注，而且只要上市，也就证明公司的注册资本、人员、管理水平等已上了一个台阶，比较规范，社会上那么多的不相关人士都会增加对上市公司的信任度。同时大明与太钢合作准备在武汉成立加工中心，预计明年5月开工建设，目前正在做可行性报告及公司营业执照注册等工作。从产业竞争角度来讲，一方面上市可以支持企业更快速地成长以取得在同行业领先的时机，另一方面，如果同行竞争者均已上市，企业同样需要充足资本与竞争对手对抗。上市也有一定的负面之处。首先每季度需要公布上市公司的财务报表及投资项目等，上市公司需要让股民知道拿着这些钱干什么。同时竞争对手也会看到上市公司的这些数据，因此保密性不强。其次上市会造成控制权失控。一上市随着时间的推移，上市公司的股份会变成全流通，这个时候一些有钱人就会轻而易举的把上市公司买走，让上市公司改名换姓。SearchImagesVideosMapsShoppingTranslateMore▼TranslateFrom:EnglishTo:Chinese(Simplified)EnglishSpanishFrenchTradeEquilibriumPrice

Itiscrucialtonotethattheimportdemandandexportsupplycurvesarenotthemselves

typicaldemandandsupplycurves.Eachofthemalreadyhaswithinitawholestructureof

productionanddemand.

RealIncomes,Production,ElasticitiesandtheTradePattern(appendix)

[ThefollowingisbasedontheappendicesofCavesandJones.]

Wewouldliketobeginbysettingoutthesourcesofwelfarecharges.Afirstexaminationshows

thatthesecancomeaboutdueto(1)changesinthetermsoftrade,or(2)endowmentchanges.

Therelevantexpression,whereRYreferstorealincomeinunitsoftheYgood:

Thisformidable-lookingexpressionactuallyhassomeintuitivecontent.Wehavechosento

measurewelfareintermsofyourrealconsumptionmeasuredinunitsoftheimportableYgood.

Notsurprisinglythen,thechangeinwelfareisgivenbythechangeinconsumptionthatis

attained--viz.PdDX+dDY(notethatthepriceconvertsunitsofXinto“real”terms,i.e.unitsof

Y).Thefinalexpressionofthishastwoterms.Thefirstisa“termsoftrade”effect.Notingthat

whenpˆ−1>0thenthepriceoftheimportablehasrisenrelatively,orequivalentlythetermsof

tradehaveworsened,wearenotsurprisedtofindthatthislowerswelfare.Thesecondtermis

lookingattheeffectsofsmallshiftsinourproductionbundle.Assumingthatwemaintainfull

employment,soremainonthePPF,thefirstordereffectofthesechangesiszero.Thereasonis

thatwewerealreadyatanoptimum,soalongthePPFMRT=dY/dX=-P.Butsimply

multiplyingandrearrangingthenshowsPdX+dY=0.[Themoreadvancedstudentmay

recognizethisasanexampleoftheWong/Vinerenvelopetheorem.]Whenthetermsoftradechange,whathappenstothedomesticdemandforimports?Thisisa

complicatedquestion.Wehavetoconsidersubstitutioneffectsandincomeeffectsindemand,as

wellasanyinducedeffectsonsupply.Theexpressionwhichwewillderivereflectsallofthese:

Ourdecisionsaboutimportsandexportsareintimatelylinkedbytherequirementof

balancedtrade.Whatdoesthissuggestabouttherelationoftheelasticitiesofimportdemandand

exportsupply?Firstletusrecallthedefinitionsofeachoftheseterms:

ElasticityofimportdemandWewouldliketohaveanideahowthetermsoftradeadjusttoexogenouschanges

(anythingbutprices)inimportdemandsinthetwocountries.Theresultthatwewillderiveis

thatthetermsoftradewillturnagainstwhicheverhasthelargerproportionalgrowthinimport

demandatunchangedprices:

III.TheRicardianModel

Inthelastchapterweestablishedanimportantprinciple:Ifautarkyrelativepricesdiffer,

itispossibleforcountriestotradeatanintermediatepriceratiosuchthatbothmaygain.Our

developmentoftheworldequilibriumwasinverygeneraltermsbasedondemandandsupplyin

eachcountry.Howeveritwasleftunexplainedwhyautarkypricesshoulddiffer.Thepresent

chapterdevelopstheRicardianmodeloftrade,andusestheconceptofcomparativeadvantage

asthebasisoftrade.WewillseethatintheRicardianmodel,thiscomparativeadvantagederives

fromunderlyingdifferencesinthetechnologyavailabletoeachcountry.

DerivationoftheRicardianPPF

Onefactor(labor)infixedsupply

TwoGoods:XandY

Thetechnologyisfullydescribedbytheconstantunitlaborinputs:aLXandaLY

Factormarketclearingrequires:

MRT=aLX/aLYdefinesthemarginalrateoftransformation,whichtellshowmuchYmustbe

reducedtoproduceonemoreunitofX(notethatitisconstanthere).[seeFigure1]

AutarkyEquilibriuminaRicardianWorld

Wewillassumehomogeneoushomotheticpreferencessothatwecanusetheconstructofa

singlerepresentativeconsumer.

Assumingthatbothgoodsareproduced,theoptimalityconditionsinacompetitiveeconomy

insurethat:AbilitytoTransform

MRS=[∂U/∂X]/[∂U/∂Y]

WillingnesstoSubstitute

Homogeneouspreferencesmeanseverybodyinthesocietyhasthesamepreferences.

HomotheticpreferencesmeanthatforagivenrelativepriceP,theproportioninwhichthegoods

areconsumedisindependentofthelevelofincome.[Theseallowustoputasideforthemoment

problemsofincomedistribution.]

RicardianSupplyandDemand

Thepricesofthegoodsproduceddependonlaborcosts.Ifanypricewasstrictlyaboveitslabor

costs,thenassumingagivenwageandfixedinputcoefficients,wecouldhaveinfiniteprofitsby

expandingproductionofthatgoodtoaninfinitelevel.Thustheassumptionofcompetitionand

finiteproductionlevelsinsuresthatthepricemustbelessthanorequaltothelaborcosts;thatis:

PX≤waLX

andPY≤waLY

(equalityifactuallyproduced)

Ifbothgoodsareproduced,itfollowsthat:

P=PX/PY=(waLX)/(waLY)=aLX/aLY=MRT

SowecandrawtheRicardianSupplyCurvesforXandY.Notethat,theautarkypricehasbeen

determinedevenbeforeconsideringdemand.Thedivisionofoutputbetweenthetwogoods,then

willcorrespondtothatdemandedatthesupply-determinedprice.ComparativeAdvantage

Whydocountriestrade?Whatdetermineswhichcountriesproducewhichgoods?Afirst

ideamightoccur:sincelaboristheonlyinput,homeshouldproducethosegoodswhichitcan

producewithlesslaborthantheforeigncountry.Itshouldimporttheothergoods.Thisistheso-

calledPrincipleofAbsoluteAdvantage.Bythisprinciple,ifaLX<aLX*thenweshouldexport

goodX.Butisthisanadequatecharacterizationofthedeterminantsoftrade?Whatshould

happenifthehomecountryhasanabsoluteadvantageinproducingeverygood?Inthiscase,

aLi<aLi*forallgoodsi.Shouldtheytradeatall?

Toanswerthis,wemustturntothePrincipleofComparativeAdvantage.Thisis

arguablythemostimportantresultininternationaltradetheory,andsomustbestudiedclosely.

RecallthatwehavealreadydefinedthemarginalrateoftransformationasMRTaLX/aLY.

WewillsaythathomehasacomparativeadvantageintheproductionofgoodXjust

when:Notethatintheautarkyequilibrium,wehadtheconditionthatP=MRT,soalsointheforeign

countrywehadP*=MRT*.Thus,recallingthatP=PX/PY,wehaveacomparativeadvantagein

goodXwhenP<P*,thatiswhenwehavealowerautarkyrelativepriceofgoodX.

Thismayseemabithardtofollow.Butthebasicideaissimple.Wearetherelatively

efficientproducerofX.Whenourautarkypriceislower,thismeansthatwehavetogiveupless

YtogetonemoreunitofXthanistrueintheforeigncountry.Conversely,iftheforeigncountry

weretoproduceoneunitlessofX,theycouldusetheextralabortoproducemoreYthanwe

gaveup.Intuitively,thisextraamountofYcouldbedividedupandbothwouldbebetteroff.

ComparativeAdvantage:AnExample

Herehomehasanabsoluteadvantageineachgood(check!).Howeveritscomparativeadvantage

liesingoodX,since:Thusfromanautarkyposition,ifhomeproducedonelessY,itcouldproducetwomore

X.IfforeignproducedonelessXitcouldproduce3/2moreY.Thenetgaintotheworldof

shiftingthesiteofproductionisoneXandone-halfY.Bothcouldbemadebetteroff.

Note,then,absoluteadvantageisnotanadequatedeterminantofthepatternoftrade.

AlthoughhomehasanabsoluteadvantageintheproductionofgoodY(aswellasgoodX),it

doesnotexportY.ThereasonisthatinspiteoftheabsoluteadvantageinY,ithasacomparative

disadvantageinY.

DerivationoftheRicardianWorldProductionPossibilitiesFrontier

TheworldPPFshowsthemaximumfeasiblecombinationsofXandY,giventhe

availabletechnologyandlaborsupplies.AcombinationofXandYissaidtobethemaximum

feasibleifitisnotpossibletoproducemoreofonewithoutproducinglessoftheother.Theseare

alsocalledpointsofproductionefficiency.

IfeachcountryisonitsPPF,doesitfollowthattheworldisontheworldPPF?No!It

maybethatthedistributionofproductionacrosscountriesisaccomplishedinefficiently.Insuch

acase,byshiftingthesiteofproductionofeachgoodtothecountrywithcomparativeadvantage

ofthatgood,wecanincreasetheavailabilityofsomegoodswithoutreducingtheavailabilityof

others.Thatis,wecanmovetowardsapointofworldproductionefficiency.

WewouldliketoderivetheworldPPF.Twopointsareeasilyderivable,namelythose

whenbothcountriesproduceonlyX,oronlyY.Inthiscase:

Toproceed,wemustknowthepatternofcomparativeadvantage.Suppose,asbefore,thathome

hasacomparativeadvantageingoodX.ThenMRT<MRT*.ThusifanyXatallshouldbe

produced,itshouldbeproducedinthehomecountry.Thus,startingfromapositionwhereonly

Yisproduced,havethehomecountryproduceoneunitofX;theamountofYwehavetogive

upisexactlyMRT(recallthatishowwedefinedit!).Itisobviousthatwewouldhavethehome

startproducingXfirst,sincethefactthatithasalowerMRTmeansthatwehavetogiveupless

YforthatfirstunitofX.Note,though,thatsincethelaborinputrequirementsareconstantfor

eachcountry,thesamemustbetrueoftheirratio,theMRT.Thatis,foreachextraXwe

produce,wehavetogiveupMRTunitsofY.Thiscontinuestobetrueupuntilthepointthat

homeiscompletelyspecializedinX.IfwewanttheworldtoproduceyetmoreX,thenthe

foreigncountrywillhavetostartproducingit.But,nowthattheforeigncountrystartstoproduce

it,wehavetogiveupmoreYtogetaunitofX,sinceMRT*>MRT.

NotethatifactualproductionistotheleftofthekinkintheworldPPF,thentheprice

undertradeisequaltothehomeautarkyprice:PT=PA=MRT.Ifweactuallyproducetothe

rightofthekink,thenPT=PA*=MRT*.Ifweactuallyproduceatthekink,thenallthatwecan

sayisthatthetradepriceisintherange:PT∈[PA,PA*].TodeterminetheactualpointontheworldPPFwherewewillproduce,wehavetolook

atworlddemandandsupply.Asbefore,assumeMRT<MRT*,andthepricesarePPX/PY.

Notethattheworldsupplycurveisinthenatureofastepfunction.Thiscorrespondstothe

conditionthatacountrywillproducebothgoodsonlyifP=MRTinthatcountry.Thusthe

horizontalsectionsoccuratthelevelsatwhichP=MRTintherespectivecountries.Wecanthen

definethreeregionsinwhichbothgoodsaresupplied.Atapriceequaltothehomeautarky

price,PT=MRTonlyhomewillproduceX(althoughitmayproducesomeYaswell);foreign

willspecializeinY.AtapricesuchthatMRT<PT<MRT*,bothcountriesspecialize--homein

goodXandforeigningoodY.AtatradepricesuchthatPT=MRT*thehomecountrywill

specializeingoodXandtheforeignwillbewillingtoproduceanyfeasiblecombinationofgood

XandY.Ofcourse,giventhesupplyconditions,thepricesandquantitiesdependonthedemand

conditions.However,notethatsmallshiftsindemandaffectproductionlevelsonlywhenoneof

thecountriesisproducingbothgoods.Further,inthiscase,thepriceiswhollyunaffected.Onthe

otherhand,ifbothcountriesarecompletelyspecialized,thensmallshiftsindemandleadtono

changeinproductionlevels,onlyachangeinthepricelevel!RicardianGainsFromTrade

Solongasthetradepricesdifferfromautarkyprices,therearegainstotrade.Ingeneral,

thegainswillbelargerthelargerthedivergence.

RelativeWagesinaRicardianWorld

TheRicardianmodelcanbeusedtotakeafistlookatwhatmightgiverisetothe

observeddistributionofwagesintheworld.

Ifbothcountriesspecialize,whichoccurswhenMRT<PT<MRT*,itmustbetruethat

PX=waLXandPY=w*aLY*.

Thisimpliesthatw/w*=[PX(1/aLX)]/[PY(1/aLY*)].Notethat1/aLXisthemarginal

productoflabor,soPX(1/aLX)givesthevalueofthemarginalproductforgoodX.Thustheratio

ofwagesbetweenthetwocountriesequalstheratioofthevalueoftherespectivemarginal

products.NotethatashiftofdemandthatraisedP=PX/PYyetstillleftproductioncompletely

specializedwouldraisehomerelativewages.

Wecansayabitmoreaboutrelativewagesinthisfirstcase.Solongasthetradeprices

are(weakly)betweentheautarkyprices,wecangiveaboundforrelativewages(alsoknownas

thefactoraltermsoftrade):Ifhomespecialized,butforeigndidnot,thenitmustbethecasethat:

PX=waLX=w*aLX*andsow/w*=aLX*/aLX.

Thatis,hererelativewagesarefixedwhollybythetechnicaldifferencesinthegoodproducedin

common.Thisistruesolongasonedoesnotspecialize.

SmallRicardianEconomyCapableofProducingNGoods

Bydefinition,asmallRicardianeconomyfacesfixedpricesforitsoutput.Evenifitis

capableofproducingNgoods,itwillspecializeinone(orseveralintheknife-edgecaseofatie)

forwhichthereisthelargestvalueofthemarginalproduct:Pi(1/aLi)=VMPi(recall1/aLiisthe

marginalproductinthei'thgood.TherewillbeatieifandonlyifPi/Pj=aLi/aLj.

NoticethatthissuggeststhatifweactuallylivedinaRicardianworldtherewouldlikely

beaveryhighdegreeofspecialization.AsalwaysinaRicardianmodel,wehavethetechnical

coefficients(herethelaborinputrequirements)independentofthelevelofoutput.Laboris

assumedtobehomogeneousandperfectlymobiledomestically.

TechnicalProgressinaRicardianModel&DistributionoftheGains

Bydefinition,asmallRicardianeconomyfacesfixedpricesforitsoutput.Evenifitis

capableofproducingNgoods,itwillspecializeinone(orseveralintheknife-edgecaseofatie)

forwhichthereisthelargestvalueofthemarginalproduct:Pi(1/aLi)=VMPi(recall1/aLiisthe

marginalproductinthei'thgood.TherewillbeatieifandonlyifPi/Pj=aLi/aLj.

NoticethatthissuggeststhatifweactuallylivedinaRicardianworldtherewouldlikely

beaveryhighdegreeofspecialization.AsalwaysinaRicardianmodel,wehavethetechnical

coefficients(herethelaborinputrequirements)independentofthelevelofoutput.Laboris

assumedtobehomogeneousandperfectlymobiledomestically.

TechnicalProgressinaRicardianModel&DistributionoftheGains

Letfivegoodsbeproduced:goodsonetothreeathomeandfourandfiveabroad.Supposethere

istechnicalprogressingoodone(i.e.aL1falls).Supposefurtherthatwisfixed(sopricesof

goodstwoandthreearefixed).Whatwillhappentothewelfareofthetwocountries?

1.IfP4andP5remainunchanged,bothbenefitaswageratesarethesameandP1has

fallen.

2.IfP4andP5rise,saybecausedemandforgoodoneisinelastic,theforeigncountrywill

definitelygain,butitispossibleherethatthehomecountrywilllose.[Jones80-81saysthat

thereisnecessarilyalosstohomeifconsumptionisinfixedproportions].

3.IfP4andP5fall,thenhomemustgain,butforeigncouldgainorlose.Thismightbethe

case,say,ifgoodoneisasubstituteforgoodsfourandfive.

NontradedGoodsintheRicardianSmallOpenEconomy

Nontradedgoodsarethoseforwhichtransportcostsmaketradeinsuchgoods

prohibitivelycostly(e.g.land,haircuts,etc.].Asbefore,thesmallopeneconomywillproduce

onlythattradedgoodforwhichPi/aLiisamaximum.Itwillimportallothertradablegoodsthatit

consumes.Butweknowthatthisgivesthewageratew=Pi/aLi.Thusgiventhetechnologyofthe

nontradedgood,andspecificallyitsunitlaborrequirement,wemusthavePNT=waLNTasits

price.Notethatourassumptionsonhowspecializationintradedgoodsoccursimpliesthat

relativelysmallchangesinrelativetradedpricescanleadtoacompletechangeintraded

specialization.ThisisnotsurprisinggiventherigidRicardiantechnicalconditionsthatwehave

specified.Whatisnoteworthyisthatthesmallshiftinpriceswillchangethewage,andsothe

priceofthenontradedgood,butitwillnotleadtothesameviolentchangeinproduction.The

nontradedsectorisabletoadjustpricesandproductionlevelswithrelativelyminorfluctuations.

Thenontradedsectorcanpassontheincreasedlaborcosts,whiletheoriginaltradedsector

cannot.Notethatwecouldhavedoneanessentiallyidenticalcomparativestaticiftherewas

technicalchangeinthetradedgoods.Whatdoesthissuggestaboutthepossibleadvantagesand

disadvantagesofanopeneconomy?[DuetoCaves/Jones].IntraindustryTradeintheRicardianEconomy

Inrecentyears,anumberofinternationaleconomistshavemademuchofthefactthat

muchofworldtradeis“intraindustry”trade--thatis,tradeisingoodsofsimilarfactorintensity.

Aswewillseelater,theyhavearguedthatwecanaccountforsuchatradeonlyifweturnto

increasingreturnstoscaleandimperfectcompetition.However,theyignoredtheverysimplest

model--thatofRicardo.Sincethereisonlyonefactor,goodsnecessarilyhaveidenticalfactor

“intensity.”Thatis,thesimpleRicardianmodelistheparadigmaticmodelofcompetitive

intraindustrytrade.Aswewillseelater,thiscanbegeneralizedtoaworldwithmoregoodsand

factors.Theimportantpointisthatwhentherearegoodsthatareexcellentsubstitutesin

production,thentechnicaldifferencesmatter.Iftheseleadtostrongspecialization,thensimilar

countriesmayengageinintraindustrytrade.

RicardianWorldwithInternationalLaborMobility

ItisleftambiguouswhethertheRicardiantechnologicaldifferencesaredueto

differencesintheworkersthemselvesorothertechnicalconditions.Assumingthelatter,perfect

labormobilitywillinsurethatunderconditionsofcompetition,thesiteofproductionwillbe

determinedbyabsoluteadvantage.Ifonecountryhasanabsoluteadvantageinbothgoods,the

othercountryceasestoexist.AssumeaLX<aLX*butaLY>aLY*.ThenallXisproducedathome

andallYisproducedabroad.ThenewworldPPFliesoutsidetheoldworldPPF,touchingit

onlyatthepointofinitialcompletespecialization.Theslopeis-aLX/aLY*.

RicardianProblem

T,F,oruncertain?Byopeningtotrade,weriskhavingone(ormore)ofourindustrieswholly

eliminatedduetocompetition.Thisraisesgravedoubtsaboutthepossibilityofenjoyinggains

fromtrade.Surprisingly,intheRicardianworld,losinganindustryisanecessaryconditionfora

countrytoexperiencegainsfromtrade.Thereasonissimple.Itwillmaintainallindustriesonly

intheeventthattradeandautarkypricesareequal.Butthisisexactlytheconditionforenjoying

nogainsfromtrade!Hereitmaybesignificantthatweareabletoabstractfromthe

macroeconomicissuesoffullemployment,sincewewouldwanttobesurethatthereleaseof

factorsinonesectorhereallowsexpansioninarelativelymoreefficientsector.

RicardianProblem

T,F,oruncertain?InaworldRicardianeconomyinwhichtwocountriesinitiallyproducethe

samegood,onecanbecertainofcapturingtheentiremarketifitexperiencesfastertechnical

growth.SincebothproducegoodX,say,wemusthavewaLX=PX=PX*=w*aLX*.Theone

thatendsupwiththelowerpricecapturetheentiremarket.Wecanseethatthisdependsnotonly

ontherateoftechnicalchange,butalsoonthegrowthrateofwagesgenerallyineachcountry.

[showproportionalchanges.]

IV.TheHeckscher-Ohlin-SamuelsonModel:TheFactor

ProportionsTheory

Inthischapterwewilldevelopthefactorproportionstheoryofinternationaltrade.Our

jobofanalyzingtradeherewillbeeasierifwefirstreviewafewmicroeconomicprinciplesand

developafewusefuldiagramsthatillustratethese.

Isoquants,IsocostLinesandtheLernerDiagram

Indevelopingourintuitionregardingthedeterminantsofpatternsofinternationaltrade,it

isusefultohavesomebasicdiagramsthathelpustothinkabouttheimplicationsofchangesin

theeconomicenvironment.OnebasicbuildingblockistheLernerdiagram.Toderiveit,though,

wemustbeginbyreviewingthemeaningofanisoquant.

Itmaybeworthwhilerecallingthattheterm"iso-"meansessentially"constant."Soan

isoquantisalinealongwhichthequantityproducedisconstant.TheisoquantforagoodXis

drawnwiththeaxesgivenbythefactorinputsusedtoproducethatgood.Inourwork,wewill

havetwofactors,capitalandlabor,andsothesewillcorrespondtoouraxes.Ifwedrawaunit

isoquantofX,wewillshowthecombinationsofKandLthatarejustcapableofproducingone

unitofX.Notethatingeneralasweusemorelabor,wecanuselesscapital,buteachtimethat

wedothistheamountoflaborthatwehavetoaddincreasesaswehavelessandlesscapital,yet

keepproducingoneunitofX.Thisgivestheisoquantthefamiliar"bowed-in"shape,convexto

theorigin.SincetheMRTS(marginalrateoftechnicalsubstitution)istheslopeoftheisoquant,

wecanseethatthiscorrespondstodiminishingMRTSaslaborissubstitutedforcapital.[see

figure1]

GiventhataunitofoutputcouldbeproducedwithanyofthedifferentcombinationsofK

andLalongtheisoquantcurve,theproducerisfacedwiththeproblemofchoosingwhichtouse.

Theobviousansweristochoosetheonethatproducesthegivenoutputatleastcost.Fromthe

perspectiveoftheindividualproducer,thefactorpriceratio,w/r,isbeyondhercontrol.

Thus,foranygivenfactorpriceratiowecandrawalineincapital/laborspacewithslope-w/r

thatisanisocostline.Thatis,everycombinationofKandLonthatlinewillbesuchthat(wL+

53

rK)equalsthesameconstantnumber.[seefigure2]Obviouslylineswiththesameslopebut

furtherfromtheoriginrepresenthigherlevelsofcosts.[Bynowyoushouldseethesymmetry

betweentheseisocostlinesandtheconsumer'stypicalbudgetline,or"iso-expenditure"line.]

Thusthewaytoproduceitatleastcostistopickthepointoftangencybetweentheisoquantand

theisocostlineforthegivenw/r.Thispointoftangencygivestheoptimalcapitaltolaborratio

forthegivenw/r.[seefigure3]Moreover,verysignificantly,wecannotethatasw/rrises(the

isocostcurvesbecomesteeper)theoptimalcapitaltolabormixwillrise.[seefigures4]This

shouldnotbesurprising--asthecostoflabor(thewage)risesrelativetocapital(therentalcost)

weshouldsubstitutetowardthefactorthathasbecomerelativelycheaper(capitalhere).This

establishesthefactthat,sayforgoodX,theoptimalkXwillbemonotonicallyincreasinginw/r.

Geometricallythiscorrespondstoasteeperlinefromtheorigintothepointoftangency.[see

figure5]Moreover,thefactthatweareworkingwithaconstantreturnstoscaleproduction

functionmeansthattheoptimalcapitaltolabormixdependsonlyonthefactorpriceratio--not

onthescaleofproduction.[seeappendixonCRSproductionfunctions]

Figure5

Bylookingattheexchangemodel,wehavealreadydevelopedarelativelysophisticated

notionofdemand.Nowweneedtoaddproduction,whichitturnsoutisverysimplehere.As

pricechanges,productionmovesalongthePPF.ThuswecansummarizesupplyofXasX=

X(P).SinceP=PX/PYweeasilyverifythatthesupplyofXisincreasinginP.SimilarlyY=Y(P-

1

besurprising.AriseinPnecessarilymeansafallinP-1,soariseinproductionofXandafallin

productionofY.

Wecannowinsertthisdirectlyintotheframeworkofimportdemand/exportsupplythat

wedevelopedearlier--onlynowwithproductionvariable.Letuslookatthehomecountryfirst.

Whatwouldtheautarky(pre-trade)situationlooklike?Wecanseethatinthiscompetitive

economy,productionandconsumptionwouldoccuratacommonpoint,whereMRS=MRT=

PA,andwhereMRTS=w/r(sincewehavefullemploymentandareonthePPF).[seeFigure14]

Thiswouldputusattheautarkyequilibrium,pointA.Intheimportdemand/exportsupply

diagram,thisimpliesMY=0justwhenP=PA.

Wecontinuetoderivetheimportdemandschedulejustasbefore,onlynowweallowfor

productiontovary.Forexample,wecouldaskwhatwouldhappenifPwerePB>PA(i.e.PB-1<

PA-1).ItisclearthatproductionshiftstowardX.Consumptionmovesinthemannerdevelopedin

theearliersection.OureconomywouldimportYandexportX.

Thesamecommentsregardingtheeffectsofpricesonsupplyanddemandholdhereforthe

foreigncountry.

Balancedtradeobtainsexactlywhereourdemandforimportsequalstheirsupplyof

exports(bothofY).Noteinthederivationthatthehomeimportdemandcutstheverticalcurveat

theautarkyprice.Correspondingly,exportsupplyisEX=X(P)−DX(P,R)=EX(P,R).

50EnglishSpanishArabic贸易平衡价格

关键是要注意的进口需求和出口供给曲线本身并不

典型的需求和供给曲线。他们每个人都已经在它的整体结构

生产和需求。

实际收入，生产，弹性和贸易格局（附录）

[以下基础上的洞穴和琼斯的附录。

我们希望开始列明福利费用的来源。第一个检查显示

这些可以来约因（1）贸易条件的变化，或（2）养老变化。

有关的表达，其中RY是指在良好的Y单位的实际收入：

这一艰巨的前瞻性的表达，实际上有一些直观的内容。我们选择

衡量您的真实单位导入Ÿ良好的消费方面的福利。

不出意料的话，消费的变化，那就是福利的变化

达到-即。P级DDX+DDY（注意，价格转换成“真实”的条款，即单位X单位

Y）在这最后的表达，有两个方面。首先是“贸易条款”的影响。注意到

当p-1>0，则导入的价格已上升相对，或等价的条款

贸易恶化，我们并不感到惊讶地发现，这降低了福利。第二项是

看在我们的生产包的小变化的影响。假设我们保持充分

就业，所以留在PPF的，这些变化的一阶效应是零。原因是

我们已经在一个最佳的，因此沿PPF的捷运=DY/DX=-P。但仅仅

相乘，然后重新排列，显示P级DX+DY=0。[更先进的学生可

承认黄/的瓦伊纳信封定理的例子。贸易变化的条款，当进口的国内需求会发生什么？这是一个

复杂的问题。我们要考虑需求替代效应和收入效应，作为

以及供应任何诱导作用。我们将获得的表达反映所有这些：

我们决定对进口和出口密切相关的要求

贸易平衡。这是什么进口需求弹性的关系，并建议有关

出口供应量呢？首先让我们回顾这些条款的定义：

进口需求弹性，我们想有一个想法，贸易条件如何调整外生变化

（除了价格），在这两个国家的进口需求。我们会得到的结果是

贸易条件会变成对进口中的比例增长，具有较大的为准

需求不变的价格：

第三。李嘉图模型

在最后一章中，我们建立了一个重要的原则：如果自给自足的相对价格差异，

它有可能为国家交易的中间价格比等，都可能获得。我们的

世界平衡发展，是基于需求和供给非常笼统

每一个国家。然而，它留给不明为什么自给自足的价格应该有所不同。本

章开发李嘉图贸易模型，并利用比较优势的概念

作为贸易的基础。我们将会看到，在李嘉图模型，这种比较优势派生

从底层的技术提供给每个国家的差异。

李嘉图人民警察的推导

在定点供应的因素之一（劳动）

X和Y两种商品：

该技术是完全描述不断单位劳动投入：ALX和ALY

要素市场的结算要求：

捷运=AL