曼昆哈佛大学经济学原理课件第二章.ppt

,ThinkingLikeanEconomist,Chapter2,Copyright2001byHarcourt,Inc.Allrightsreserved.Requestsforpermissiontomakecopiesofanypartoftheworkshouldbemailedto:PermissionsDepartment,HarcourtCollegePublishers,6277SeaHarborDrive,Orlando,Florida32887-6777.,Everyfieldofstudyhasitsownterminology,Mathematics,Psychology,Law,Everyfieldofstudyhasitsownterminology,Economics,Supply,Demand,Elasticity,ConsumerSurplus,Comparativeadvantage,Opportunitycost,Deadweightloss,Economicstrainsyouto.,Thinkintermsofalternatives.Evaluatethecostofindividualandsocialchoices.Examineandunderstandhowcertaineventsandissuesarerelated.,TheEconomistasaScientist,Theeconomicwayofthinking.Involvesthinkinganalyticallyandobjectively.Makesuseofthescientificmethod.,TheScientificMethod,Usesabstractmodelstohelpexplainhowacomplex,realworldoperates.Developstheories,collects,andanalyzesdatatoprovethetheories.,Observation,TheoryandMoreObservation!,TheRoleofAssumptions,Economistsmakeassumptionsinordertomaketheworldeasiertounderstand.Theartinscientificthinkingisdecidingwhichassumptionstomake.Economistsusedifferentassumptionstoanswerdifferentquestions.,TheEconomicWayofThinking,Includesdevelopingabstractmodelsfromtheoriesandtheanalysisofthemodels.Usestwoapproaches:,Descriptive(reportingfacts,etc.)Analytical(abstractreasoning),EconomicModels,EconomistsusemodelstosimplifyrealityinordertoimproveourunderstandingoftheworldTwoofthemostbasiceconomicmodelsinclude:,TheCircularFlowModel,TheProductionPossibilitiesFrontier,TheCircular-FlowModel,Thecircular-flowmodelisasimplewaytovisuallyshowtheeconomictransactionsthatoccurbetweenhouseholdsandfirmsintheeconomy.,TheCircular-FlowDiagram,Firms,Households,MarketforFactorsofProduction,MarketforGoodsandServices,TheCircular-FlowDiagram,HouseholdsBuyandconsumegoodsandservicesOwnandsellfactorsofproduction,FirmsProduceandsellgoodsandservicesHireandusefactorsofproduction,TheCircular-FlowDiagram,MarketsforFactorsofProductionHouseholdssellFirmsbuy,MarketsforGoods&ServicesFirmssellHouseholdsbuy,TheCircular-FlowDiagram,FactorsofProductionInputsusedtoproducegoodsandservicesLand,labor,andcapital,TheProductionPossibilitiesFrontier,Theproductionpossibilitiesfrontierisagraphshowingthevariouscombinationsofoutputthattheeconomycanpossiblyproducegiventheavailablefactorsofproductionandtechnology.,TheProductionPossibilitiesFrontier,QuantityofComputersProduced,QuantityofCarsProduced,3,000,1,000,TheProductionPossibilitiesFrontier,QuantityofComputersProduced,QuantityofCarsProduced,3,000,1,000,2,000,2,200,A,700,600,300,0,1,000,B,C,D,Production,possibilities,frontier,ConceptsIllustratedbytheProductionPossibilitiesFrontier,EfficiencyTradeoffsOpportunityCostEconomicGrowth,TheProductionPossibilitiesFrontier,QuantityofComputersProduced,QuantityofCarsProduced,3,000,2,000,A,700,0,1,000,Anoutwardshiftintheproductionpossibilitiesfrontier,MicroeconomicsandMacroeconomics,Microeconomicsfocusesontheindividualpartsoftheeconomy.HowhouseholdsandfirmsmakedecisionsandhowtheyinteractinspecificmarketsMacroeconomicslooksattheeconomyasawhole.Howthemarkets,asawhole,interactatthenationallevel.,TwoRolesofEconomists,Whentheyaretryingtoexplaintheworld,theyarescientists.Whentheyaretryingtochangetheworld,theyarepolicymakers.,PositiveversusNormativeAnalysis,Positivestatementsarestatementsthatdescribetheworldasitis.CalleddescriptiveanalysisNormativestatementsarestatementsabouthowtheworldshouldbe.Calledprescriptiveanalysis,?,?,PositiveorNormativeStatements?,Anincreaseintheminimumwagewillcauseadecreaseinemploymentamongtheleast-skilled.,?,?,?,PositiveorNormativeStatements?,Higherfederalbudgetdeficitswillcauseinterestratestoincrease.,?,?,?,?,PositiveorNormativeStatements?,Theincomegainsfromahigherminimumwageareworthmorethananyslightreductionsinemployment.,?,?,?,PositiveorNormativeStatements?,Stategovernmentsshouldbeallowedtocollectfromtobaccocompaniesthecostsoftreatingsmoking-relatedillnessesamongthepoor.,EconomistsinWashington.,.serveasadvisersinthepolicymakingprocessofthethreebranchesofgovernment:LegislativeExecutiveJudicial,WhyEconomistsDisagree,Theymaydisagreeontheoriesabouthowtheworldworks.Theymayholddifferentvaluesand,thus,differentnormativeviews.,ExamplesofWhatMostEconomistsAgreeOn,Aceilingonrentsreducesthequantityandqualityofhousingavailable.Tariffsandimportquotasusuallyreducegeneraleconomicwelfare.,Summary,Inordertoaddresssubjectswithobjectivity,economicsmakesuseofthescientificmethod.Thefieldofeconomicsisdividedintotwosubfields:microeconomicsandmacroeconomics.,Summary,Economicsreliesonbothpositiveandnormativeanalysis.Positivestatementsasserthowtheworld“is”whilenormativestatementsasserthowthew