北大微觀經(jīng)濟(jì)學(xué)(英文版)-課件

ChapterTwenty-NineExchange1ppt課件ExchangeTwoconsumers,AandB.Theirendowmentsofgoods1and2are

E.g.Thetotalquantitiesavailableandandunitsofgood1unitsofgood2.andare2ppt課件ExchangeEdgeworthandBowleydevisedadiagram,calledanEdgeworthbox,toshowallpossibleallocationsoftheavailablequantitiesofgoods1and2betweenthetwoconsumers.3ppt課件StartinganEdgeworthBox4ppt課件StartinganEdgeworthBoxWidth=5ppt課件StartinganEdgeworthBoxWidth=Height=6ppt課件StartinganEdgeworthBoxWidth=Height=Thedimensionsof

theboxarethe

quantitiesavailable

ofthegoods.7ppt課件FeasibleAllocationsWhatallocationsofthe8unitsofgood1andthe6unitsofgood2arefeasible?HowcanallofthefeasibleallocationsbedepictedbytheEdgeworthboxdiagram?8ppt課件FeasibleAllocationsWhatallocationsofthe8unitsofgood1andthe6unitsofgood2arefeasible?HowcanallofthefeasibleallocationsbedepictedbytheEdgeworthboxdiagram?Onefeasibleallocationisthebefore-tradeallocation;i.e.theendowmentallocation.9ppt課件Width=Height=Theendowment

allocationisandTheEndowmentAllocation10ppt課件Width=Height=TheEndowmentAllocation11ppt課件OAOB68TheEndowmentAllocation12ppt課件OAOB6846TheEndowmentAllocation13ppt課件OAOB684622TheEndowmentAllocation14ppt課件OAOB684622The

endowment

allocationTheEndowmentAllocation15ppt課件Moregenerally,…TheEndowmentAllocation16ppt課件TheEndowmentAllocationOAOBThe

endowment

allocation17ppt課件OtherFeasibleAllocations

denotesanallocationtoconsumerA.denotesanallocationtoconsumerB.Anallocationisfeasibleifandonlyifand18ppt課件FeasibleReallocationsOAOB19ppt課件FeasibleReallocationsOAOB20ppt課件FeasibleReallocationsAllpointsinthebox,includingtheboundary,representfeasibleallocationsofthecombinedendowments.21ppt課件FeasibleReallocationsAllpointsinthebox,includingtheboundary,representfeasibleallocationsofthecombinedendowments.Whichallocationswillbeblockedbyoneorbothconsumers?Whichallocationsmakebothconsumersbetteroff?22ppt課件AddingPreferencestotheBoxOAForconsumerA.23ppt課件AddingPreferencestotheBoxMorepreferredForconsumerA.OA24ppt課件AddingPreferencestotheBoxForconsumerB.OB25ppt課件AddingPreferencestotheBoxMorepreferredForconsumerB.OB26ppt課件AddingPreferencestotheBoxMorepreferredForconsumerB.OB27ppt課件AddingPreferencestotheBoxOAForconsumerA.28ppt課件AddingPreferencestotheBoxOAOB29ppt課件Edgeworth’sBoxOAOB30ppt課件Pareto-ImprovementAnallocationoftheendowmentthatimprovesthewelfareofaconsumerwithoutreducingthewelfareofanotherisaPareto-improvingallocation.WherearethePareto-improvingallocations?31ppt課件Edgeworth’sBoxOAOB32ppt課件Pareto-ImprovementsOAOBThesetofPareto-

improvingallocations33ppt課件Pareto-ImprovementsSinceeachconsumercanrefusetotrade,theonlypossibleoutcomesfromexchangearePareto-improvingallocations.ButwhichparticularPareto-improvingallocationwillbetheoutcomeoftrade?34ppt課件Pareto-ImprovementsOAOBThesetofPareto-

improvingreallocations35ppt課件Pareto-Improvements36ppt課件Pareto-Improvements37ppt課件Pareto-ImprovementsTrade

improvesboth

A’sandB’swelfares.

ThisisaPareto-improvement

overtheendowmentallocation.38ppt課件Pareto-ImprovementsNewmutualgains-to-traderegion

isthesetofallfurtherPareto-

improving

reallocations.

Trade

improvesboth

A’sandB’swelfares.

ThisisaPareto-improvement

overtheendowmentallocation.39ppt課件Pareto-ImprovementsFurthertradecannotimprove

bothAandB’s

welfares.40ppt課件Pareto-OptimalityBetterfor

consumerBBetterfor

consumerA41ppt課件Pareto-OptimalityAisstrictlybetteroff

butBisstrictlyworse

off42ppt課件Pareto-OptimalityAisstrictlybetteroff

butBisstrictlyworse

offBisstrictlybetter

offbutAisstrictly

worseoff43ppt課件Pareto-OptimalityAisstrictlybetteroff

butBisstrictlyworse

offBisstrictlybetter

offbutAisstrictly

worseoffBothAand

Bareworse

off44ppt課件Pareto-OptimalityAisstrictlybetteroff

butBisstrictlyworse

offBisstrictlybetter

offbutAisstrictly

worseoffBothA

andBare

worse

offBothAand

Bareworse

off45ppt課件Pareto-OptimalityTheallocationis

Pareto-optimalsincethe

onlywayoneconsumer’swelfarecanbeincreasedisto

decreasethewelfareoftheother

consumer.46ppt課件Pareto-OptimalityTheallocationis

Pareto-optimalsincethe

onlywayoneconsumer’swelfarecanbeincreasedisto

decreasethewelfareoftheother

consumer.Anallocationwhereconvex

indifferencecurvesare“only

justback-to-back”is

Pareto-optimal.47ppt課件Pareto-OptimalityWhereareallofthePareto-optimalallocationsoftheendowment?48ppt課件Pareto-OptimalityOAOB49ppt課件Pareto-OptimalityOAOBAlltheallocationsmarkedby

aarePareto-optimal.50ppt課件Pareto-OptimalityThecontractcurveisthesetofallPareto-optimalallocations.51ppt課件Pareto-OptimalityOAOBAlltheallocationsmarkedby

aarePareto-optimal.Thecontractcurve52ppt課件Pareto-OptimalityButtowhichofthemanyallocationsonthecontractcurvewillconsumerstrade?Thatdependsuponhowtradeisconducted.Inperfectlycompetitivemarkets?Byone-on-onebargaining?53ppt課件TheCoreOAOBThesetofPareto-

improvingreallocations54ppt課件TheCoreOAOB55ppt課件TheCoreOAOBPareto-optimaltradesblocked

byBPareto-optimaltradesblocked

byA56ppt課件TheCoreOAOBPareto-optimaltradesnotblocked

byAorB57ppt課件TheCoreOAOBPareto-optimaltradesnotblocked

byAorBarethecore.58ppt課件TheCoreThecoreisthesetofallPareto-optimalallocationsthatarewelfare-improvingforbothconsumersrelativetotheirownendowments.Rationaltradeshouldachieveacoreallocation.59ppt課件TheCoreButwhichcoreallocation?Again,thatdependsuponthemannerinwhichtradeisconducted.60ppt課件TradeinCompetitiveMarketsConsidertradeinperfectlycompetitivemarkets.Eachconsumerisaprice-takertryingtomaximizeherownutilitygivenp1,p2andherownendowment.Thatis,...61ppt課件TradeinCompetitiveMarketsOAForconsumerA.62ppt課件TradeinCompetitiveMarketsSogivenp1andp2,consumerA’snetdemandsforcommodities1and2areand63ppt課件TradeinCompetitiveMarketsAnd,similarly,forconsumerB…64ppt課件TradeinCompetitiveMarketsForconsumerB.OB65ppt課件TradeinCompetitiveMarketsSogivenp1andp2,consumerB’snetdemandsforcommodities1and2areand66ppt課件TradeinCompetitiveMarketsAgeneralequilibriumoccurswhenpricesp1andp2causeboththemarketsforcommodities1and2toclear;i.e.and67ppt課件TradeinCompetitiveMarketsOAOB68ppt課件TradeinCompetitiveMarketsOAOBCanthisPOallocationbeachieved?69ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerA70ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerA71ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerB72ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerB73ppt課件TradeinCompetitiveMarketsOAOBBut74ppt課件TradeinCompetitiveMarketsOAOBand75ppt課件TradeinCompetitiveMarketsSoatthegivenpricesp1andp2thereisanexcesssupplyofcommodity1excessdemandforcommodity2.Neithermarketclearssothepricesp1andp2donotcauseageneralequilibrium.76ppt課件TradeinCompetitiveMarketsOAOBSothisPOallocationcannotbeachievedbycompetitivetrading.77ppt課件TradeinCompetitiveMarketsOAOBWhichPOallocationscanbe

achievedbycompetitivetrading?78ppt課件TradeinCompetitiveMarketsSincethereisanexcessdemandforcommodity2,p2willrise.Sincethereisanexcesssupplyofcommodity1,p1willfall.Theslopeofthebudgetconstraintsis-p1/p2sothebudgetconstraintswillpivotabouttheendowmentpointandbecomelesssteep.79ppt課件TradeinCompetitiveMarketsOAOBWhichPOallocationscanbe

achievedbycompetitivetrading?80ppt課件TradeinCompetitiveMarketsOAOBWhichPOallocationscanbe

achievedbycompetitivetrading?81ppt課件TradeinCompetitiveMarketsOAOBWhichPOallocationscanbe

achievedbycompetitivetrading?82ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerA83ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerA84ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerB85ppt課件TradeinCompetitiveMarketsOAOBBudgetconstraintforconsumerB86ppt課件TradeinCompetitiveMarketsOAOBSo87ppt課件TradeinCompetitiveMarketsOAOBand88ppt課件TradeinCompetitiveMarketsAtthenewpricesp1andp2bothmarketsclear;thereisageneralequilibrium.TradingincompetitivemarketsachievesaparticularPareto-optimalallocationoftheendowments.ThisisanexampleoftheFirstFundamentalTheoremofWelfareEconomics.89ppt課件FirstFundamentalTheoremofWelfareEconomicsGiventhatconsumers’preferencesarewell-behaved,tradinginperfectlycompetitivemarketsimplementsaPareto-optimalallocationoftheeconomy’sendowment.90ppt課件SecondFundamentalTheoremofWelfareEconomicsTheFirstTheoremisfollowedbyasecondthatstatesthatanyPareto-optimalallocation(i.e.anypointonthecontractcurve)canbeachievedbytradingincompetitivemarketsprovidedthatendowmentsarefirstappropriatelyrearrangedamongsttheconsumers.91ppt課件Giventhatconsumers’preferencesarewell-behaved,foranyPareto-optimalallocationtherearepricesandanallocationofthetotalendowmentthatmakesthePareto-optimalallocationimplementablebytradingincompetitivemarkets.SecondFundamentalTheoremofWelfareEconomics92ppt課件SecondFundamentalTheoremOAOBThecontractcurve93ppt課件SecondFundamentalTheoremOAOB94ppt課件SecondFundamentalTheoremOAOBImplementedbycompetitivetradingfromtheendowmentw.95ppt課件SecondFundamentalTheoremOAOBCanthisallocationbeimplemented

bycompetitivetradingfromw?96ppt課件SecondFundamentalTheoremOAOBCanthisallocationbeimplemented

bycompetitivetradingfromw?No.97ppt課件SecondFundamentalTheoremOAOBButthisallocationisimplemented

bycompetitivetradingfromq.98ppt課件Walras’LawWalras’Lawisani