LaborProductivityandComparativeAdvantage:TheRicardianModelAnswerstoTextbookProblems1.a.Theproductionpossibilitycurveisastraightlinethatinterceptstheappleaxisat400(1200/3)andthebananaaxisat600(1200/2).b.Theopportunitycostofapplesintermsofbananasis3/2.Ittakesthreeunitsoflabortoharvestanapplebutonlytwounitsoflabortoharvestabanana.Ifoneforegoesharvestinganapple,thisfreesupthreeunitsoflabor.These3unitsoflaborcouldthenbeusedtoharvest1.5bananas.c.Labormobilityensuresacommonwageineachsectorandcompetitionensuresthepriceofgoodsequalstheircostofproduction.Thus,therelativepriceequalstherelativecosts,whichequalsthewagetimestheunitlaborrequirementforapplesdividedbythewagetimestheunitlaborrequirementforbananas.Sincewagesareequalacrosssectors,thepriceratioequalstheratiooftheunitlaborrequirement,whichis3applesper2bananas.2.a.Theproductionpossibilitycurveislinear,withtheinterceptontheappleaxisequalto160(800/5)andtheinterceptonthebananaaxisequalto800(800/1).b.Theworldrelativesupplycurveisconstructedbydeterminingthesupplyofapplesrelativetothesupplyofbananasateachrelativeprice.Thelowestrelativepriceatwhichapplesareharvestedis3applesper2bananas.Therelativesupplycurveisflatatthisprice.Themaximumnumberofapplessuppliedatthepriceof3/2is400suppliedbyHomewhile,atthisprice,Foreignharvests800bananasandnoapples,givingamaximumrelativesupplyatthispriceof1/2.Thisrelativesupplyholdsforanypricebetween3/2and5.Atthepriceof5,bothcountrieswouldharvestapples.Therelativesupplycurveisagainflatat5.Thus,therelativesupplycurveisstepshaped,flatattheprice3/2fromtherelativesupplyof0to1/2,verticalattherelativequantity1/2risingfrom3/2to5,andthenflatagainfrom1/2toinfinity.3.a.Therelativedemandcurveincludesthepoints(1/5,5),(1/2,2),(1,1),(2,1/2).b.Theequilibriumrelativepriceofapplesisfoundattheintersectionoftherelativedemandandrelativesupplycurves.Thisisthepoint(1/2,2),wheretherelativedemandcurveintersectstheverticalsectionoftherelativesupplycurve.Thustheequilibriumrelativepriceis2.c.Homeproducesonlyapples,Fo