(42)-3.1.2机会成本不变与贸易

Aproductionpossibilitiesschedule,alsocalledatransformationschedule.Thisscheduleshowsvariousalternativecombinationsoftwogoodsthatanationcanproducewhenallofitsfactorinputs(land,labor,capital,entrepreneurship)aresuedintheirmostefficientmanner.Theproductionpossibilitiesschedulethusillustratesthemaximumoutputpossibilitiesofanation.Notethatwearenolongerassuminglabortobetheonlyfactorinput,asRicardodid.Productionpossibilitiesschedule

Generalizestheorytoincludeallfactors,notjustlaborShowscombinationsofproductsthatcanbemadeifallfactorsareusedefficientlySlope,ormarginalrateoftransformation,showstheopportunitycostofmakingmoreofonegood(howmuchofonegoodmustbegivenuptomakemoreofanother)Justhowdoesaproductionpossibilitiesscheduleillustratetheconceptofcomparativecost?Theanswerliesintheslopeoftheproductionpossibilitiesschedule,whichisreferredtoasthemarginalrateoftransformation(MRT).TheMRTshowstheamountofoneproductanationmustsacrificetogetoneadditionalunitoftheotherproduct:Thisrateofsacrificeissometimescalledtheopportunitycostofaproduct.Becausethisformulaalsoreferstotheslopeoftheproductionpossibilitiesschedule,theMRTequalstheabsolutevalueoftheproductionpossibilitiesschedule’sslope.MarginalRateofTransformation

Productionpossibilitiesschedules:constantopportunitycosts

Supplyschedules:constantopportunitycosts

Tradingunderconstantopportunitycosts

Productiongainsfromspecialization:constantopportunitycosts

Before After NetGain Specialization Specialization (Loss)Autos

Wheat Autos

Wheat

Autos

WheatUS 40 40 120 0 80 -40Canada

40 80 0 160 -40 80World 80 120 120 160 40 40

Consumptiongainsfromtrade:constantopportunitycosts

Before After NetGainTrade Trade (Loss)Autos

Wheat Autos

Wheat

Autos

WheatUS 40 40 60 60 20 20Canada

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