Chap_06Supply,DemandandGovernmentPolicies(曼昆

Supply,DemandandGovernmentPoliciesChapter6Supply,Demand,andGovernmentPoliciesInafree,unregulatedmarketsystem,marketforcesestablishequilibriumpricesandexchangequantities.Whileequilibriumconditionsmaybeefficient,itmaybetruethatnoteveryoneissatisfied.Oneoftherolesofeconomistsistousetheirtheoriestoassistinthedevelopmentofpolicies.PriceControls...Areusuallyenactedwhenpolicymakersbelievethemarketpriceisunfairtobuyersorsellers.Resultingovernment-createdpriceceilingsandfloors.PriceCeilings&PriceFloorsPriceCeilingAlegallyestablishedmaximumpriceatwhichagoodcanbesold.PriceFloorAlegallyestablishedminimumpriceatwhichagoodcanbesold.PriceCeilingsTwooutcomesarepossiblewhenthegovernmentimposesapriceceiling:Thepriceceilingisnotbindingifsetabovetheequilibriumprice.Thepriceceilingisbindingifsetbelowtheequilibriumprice,leadingtoashortage.APriceCeilingThatIsNotBinding...$43QuantityofIce-CreamCones0PriceofIce-CreamConeDemandSupplyPriceceilingEquilibriumprice100EquilibriumquantityHarcourt,Inc.itemsandderiveditemscopyright©2001byHarcourt,Inc.APriceCeilingThatIsBinding...$3QuantityofIce-CreamCones0PriceofIce-CreamCone2DemandSupplyEquilibriumpricePriceceilingShortage125Quantitydemanded75QuantitysuppliedHarcourt,Inc.itemsandderiveditemscopyright©2001byHarcourt,Inc.EffectsofPriceCeilingsAbindingpriceceilingcreates...shortagesbecauseQDQS.Example:Gasolineshortageofthe1970snonpricerationingExamples:Longlines,DiscriminationbysellersLinesattheGasPumpIn1973OPECraisedthepriceofcrudeoilinworldmarkets.Becausecrudeoilisthemajorinputusedtomakegasoline,thehigheroilpricesreducedthesupplyofgasoline.Whatwasresponsibleforthelonggaslines?Economistsblamegovernmentregulationsthatlimitedthepriceoilcompaniescouldchargeforgasoline.ThePriceCeilingonGasolineIsNotBinding...$4P1QuantityofGasoline0PriceofGasolineQ1DemandSupplyPriceceiling1.Initially,thepriceceilingisnotbinding...ThePriceCeilingonGasolineIsBinding...P1QuantityofGasoline0PriceofGasolineQ1DemandS1PriceceilingS22.…butwhensupplyfalls...P23.…thepriceceilingbecomesbinding...4.…resultinginashortage.RentControlRentcontrolsareceilingsplacedontherentsthatlandlordsmaychargetheirtenants.Thegoalofrentcontrolpolicyistohelpthepoorbymakinghousingmoreaffordable.Oneeconomistcalledrentcontrol“thebestwaytodestroyacity,otherthanbombing.”RentControlintheShortRun...QuantityofApartments0RentalPriceofApartmentDemandSupplyControlledrentShortageSupplyanddemandforapartmentsarerelativelyinelasticRentControlintheLongRun...QuantityofApartments0RentalPriceofApartmentDemandSupplyControlledrentShortageBecausethesupplyanddemandforapartmentsaremoreelastic...…rentcontrolcausesalargeshortagePriceFloorsWhenthegovernmentimposesapricefloor,twooutcomesarepossible.Thepricefloorisnotbindingifsetbelowtheequilibriumprice.Thepricefloorisbindingifsetabovetheequilibriumprice,leadingtoasurplus.APriceFloorThatIsNotBinding...$3QuantityofIce-CreamCones0PriceofIce-CreamCone100EquilibriumquantityEquilibriumpriceDemandSupplyPricefloor2APriceFloorThatIsBinding...$3QuantityofIce-CreamCones0PriceofIce-CreamConeEquilibriumpriceDemandSupplyPricefloor$4120Quantitysupplied80QuantitydemandedSurplusHarcourt,Inc.itemsandderiveditemscopyright©2001byHarcourt,Inc.EffectsofaPriceFloorApricefloorpreventssupplyanddemandfrommovingtowardtheequilibriumpriceandquantity.Whenthemarketpricehitsthefloor,itcanfallnofurther,andthemarketpriceequalsthefloorprice.EffectsofaPriceFloorAbindingpricefloorcauses...asurplusbecauseQSQD.nonpricerationingisanalternativemechanismforrationingthegood,usingdiscriminationcriteria.Examples:Theminimumwage,AgriculturalpricesupportsTheMinimumWageAnimportantexampleofapriceflooristheminimumwage.Minimumwagelawsdictatethelowestpricepossibleforlaborthatanyemployermaypay.TheMinimumWageQuantityofLabor0WageEquilibriumwageLabordemandLaborsupplyAFreeLaborMarketEquilibriumemploymentMinimumwageTheMinimumWageQuantityofLabor0WageLabordemandLaborsupplyQuantitysuppliedQuantitydemandedLaborsurplus(unemployment)ALaborMarketwithaMinimumWageTaxesGovernmentslevytaxestoraiserevenueforpublicprojects.Whataresomepotentialimpactsoftaxes?Taxesdiscouragemarketactivity.Whenagoodistaxed,thequantitysoldissmaller.Buyersandsellerssharethetaxburden.TaxesTaxincidenceisthestudyofwhobearstheburdenofatax.Taxesresultinachangeinmarketequilibrium.Buyerspaymoreandsellersreceiveless,regardlessofwhomthetaxisleviedon.Impactofa50¢TaxLeviedonBuyers...3.00QuantityofIce-CreamCones0PriceofIce-CreamCone100D1Supply,S1Ataxonbuyersshiftsthedemandcurvedownwardbythesizeofthetax($0.50).D2Copyright©2001byHarcourt,Inc.Allrightsreserved3.00QuantityofIce-CreamCones0PriceofIce-CreamCone10090$3.30PricebuyerspayD1D2EquilibriumwithtaxSupply,S1EquilibriumwithouttaxImpactofa50¢TaxLeviedonBuyers...2.80PricesellersreceiveCopyright©2001byHarcourt,Inc.AllrightsreservedPricewithouttaxTax($0.50)Whatwastheimpactoftax?Taxesdiscouragemarketactivity.Whenagoodistaxed,thequantitysoldissmaller.Buyersandsellerssharethetaxburden.3.00QuantityofIce-CreamCones0PriceofIce-CreamCone10090S1S2Demand,D