Chapter-17-Public-Goods-and-Common-Resources-公共产品

•117PublicGoodsandCommonResourcesContent17.1TheDifferentKindsofGoods17.2PublicGoods17.3CommonResources•217.1TheDifferentKindsofGoods•3ExcludabilityPropertyofagoodwherebyapersoncanbepreventedfromusingitRivalryinconsumptionPropertyofagoodwherebyoneperson’susediminishesotherpeople’suse17.1TheDifferentKindsofGoods•4PrivategoodsExcludable&RivalinconsumptionPublicgoodsNotexcludable&NotrivalinconsumptionCommonresourcesRivalinconsumption&NotexcludableClubgoodsExcludable&NotrivalinconsumptionOnetypeofnaturalmonopolyFourTypesofGoods517.1TheDifferentKindsofGoods•6PublicgoodsandcommonresourcesNotexcludablePeoplecannotbepreventedfromusingthemAvailabletoeveryonefreeofchargeNopriceattachedtoitExternaleffectsPositiveexternalities(publicgoods)Negativeexternalities(commonresources)17.1TheDifferentKindsofGoods•7PublicgoodsandcommonresourcesPrivatedecisionsaboutconsumptionandproductionCanleadtoaninefficientallocationofresourcesGovernmentinterventionCanpotentiallyraiseeconomicwell-beingContent17.1TheDifferentKindsofGoods17.2PublicGoods17.3CommonResources•817.2PublicGoods•9FreeriderPersonwhoreceivesthebenefitofagoodbutavoidspayingforitThefree-riderproblemPublicgoodsarenotexcludablePreventstheprivatemarketfromsupplyingthegoods17.2PublicGoods•10Governmentcanremedythefree-riderproblem-Iftotalbenefitsofapublicgoodexceedsitscosts-Providethepublicgood-Payforitwithtaxrevenue-Makeeveryonebetteroff17.2PublicGoods•11SomeimportantpublicgoodsNationaldefenseVeryexpensivepublicgood$717billionin2011BasicresearchGeneralknowledgeSubsidizedbygovernmentThepublicsectorfailstopayfortherightamountandtherightkinds17.2PublicGoods•12SomeimportantpublicgoodsAntipovertyprograms(financedbytaxes)Welfaresystem(TemporaryAssistanceforNeedyFamiliesprogram,TANF)ProvidesasmallincomeforsomepoorfamiliesFoodstamps(SupplementalNutritionAssistanceProgram,SNAP)SubsidizethepurchaseoffoodforthosewithlowincomesGovernmenthousingprogramsMakesheltermoreaffordableArelighthousespublicgoods?•13LighthousesMarkspecificlocationssothatpassingshipscanavoidtreacherouswatersBenefit:totheshipcaptainNotexcludable,notrivalinconsumptionIncentive:freeridewithoutpayingMostareoperatedbythegovernmentArelighthousespublicgoods?•14InsomecasesLighthousesareclosertoprivategoodsCoastofEngland,19thcenturyLighthouseswereprivatelyownedandoperatedTheownerofthelighthousechargedtheownerofthenearbyportIftheportowneddidnotpay,lighthouseownerturnedthelightoffShipsavoidedthatportArelighthousespublicgoods?•15DecidewhethersomethingisapublicgoodDeterminewhothebeneficiariesareDeterminewhetherthebeneficiariescanbeexcludedfromusingthegoodAfree-riderproblemWhenthenumberofbeneficiariesislargeExclusionofanyoneofthemisimpossible17.2PublicGoods•16Thedifficultjobofcost–benefitanalysisGovernmentDecidewhatpublicgoodstoprovideInwhatquantitiesCost–benefitanalysisComparethecostsandbenefitstosocietyofprovidingapublicgoodDoesn’thaveanypricesignalstoobserveGovernmentfindingsRoughapproximationsatbestHowmuchisalifeworth?•17Cost:$10,000foranewtrafficlightBenefit:increasedsafetyRiskofafataltrafficaccidentDropsfrom1.6%to1.1%ObstacleMeasurecostsandbenefitsinthesameunitsPutadollarvalueonahumanlife?Priceless=infinitedollarvalueHowmuchisalifeworth?•18ImplicitdollarvalueofahumanlifeCourts:awarddamagesinwrongful-deathsuitsTotalamountofmoneyapersonwouldhaveearnedifheorshehadlivedIgnoresotheropportunitycostsoflosingone’slifeRisksthatpeoplearevoluntarilywillingtotakeandhowmuchtheymustbepaidfortakingthemValueofhumanlife=$10millionHowmuchisalifeworth?•19Cost-benefitanalysisTrafficlightReducesriskoffatalityby0.5percentagepointsExpectedbenefit=0.005×$10million=$50,000Cost($10,000)Benefit($50,000)ApprovethetrafficlightContent•2017.1TheDifferentKindsofGoods17.2PublicGoods17.3CommonResources17.3CommonResources•21CommonresourcesNotexcludableRivalinconsumptionThetragedyofthecommonsParablethatshowswhycommonresourcesareusedmorethandesirableFromsociety’sstandpointSocialandprivateincentivesdifferArisesbecauseofanegativeexternality17.3CommonResources•22ThetragedyofthecommonsNegativeexternalityOnepersonusesacommonresourceDiminishesotherpeople’senjoymentofitCommonresourcestendtobeusedexcessivelyGovernmentcansolvetheproblemRegulationortaxestoreduceconsumptionofthecommonresourceTurnthecommonresourceintoaprivategood17.3CommonResources•23SomeimportantcommonresourcesCleanairandwaterNegativeexternality:pollutionRegulationsorcorrectivetaxesCongestedroadsNegativeexternality:congestionCorrectivetax:chargedriversatoolTaxongasoline17.3CommonResources•24SomeimportantcommonresourcesFish,whales,andotherwildlifeOceansaretheleastregulatedcommonresourceNeedsinternationalcooperationDifficulttoenforceanagreementFishingandhuntinglicensesLimitsonfishingandhuntingseasonsLimitsonsizeoffishLimitsonquantityofanimalskilledWhythecowisnotextinct•25AnimalswithcommercialvaluethatarethreatenedwithextinctionBuffalo；Elephants--commonresourceThecowsar