微觀經(jīng)濟(jì)學(xué)講解

微觀經(jīng)濟(jì)學(xué)講解LearningObjectivesExplainhowmiddlemenaddvaluetomarkettransactionsUsetheconceptofrationalsearchtofindtheoptimalamountofinformationmarketparticipantsshouldobtainDefineasymmetricinformationanddescribehowitleadstothelemonsproblemDiscusshowadvertising,conspicuousconsumption,statisticaldiscrimination,andotherdevicesareresponsestoasymmetricinformationInformationandtheInvisibleHandAllpartieshaveallrelevantinformationWithoutfreeinformation,marketresultsarenotefficientBargainingforabowlinKashmirPartiesmustdecidehowmuchinformationtogatherInformationgatheringstrategiesdifferTheMiddlemanAddsValueBuyerssometimeschooseamongseveralversionofaproductEachhascomplexfeaturesetsResearchoptionsCompanywebsiteAskfriendsandfamilyConsumerReports,onlineproductreviewsVisitstores,ecommercesitesBuyingSkisSkisRUsrecommend$600SalomonX-Scream9skisSalesrepseemsknowledgeableYournextmoveisThankthemanddomoreresearchTrustthesalesrepandbuythemGohomeandbuyatthebestpriceonline($400)EvaluatetheimportanceofImmediatepossessionBestpricePost-salesserviceandsupportTheValueoftheMiddlemanSalesrepresentativessupplyinformationtobuyersManufacturerscanofferdirectsalestobypassmiddlemenInformationmakesmarketsmoreefficientPurchasingthebowlinKashmirSellingBabeRuthElliswantstosellaBabeRuthbaseballcard.Hisreservationpriceis$300Anadinthelocalnewspapercost$5eBaycostis5%oftheInternetauctionpriceThemaximumpriceinthelocalmarketis$400TwoeBayshoppershavesecretreservationpricesof$800and$900,respectivelySellingBabeRuthBenefitsofeBayCardsellsfor$800oneBayless$40commissionEllisnets$760,$460abovehisreservationpriceBuyersurplusis$100LocaloptionisinferiorCardsellsfor$400less$5costofadEllisnets$395,$95morethanhisreservationpriceBuyersurplusis$0Economicsurplusisincreasedwhenaproductgoestothepersonwhovaluesitthemost$/unitUnitsofinformationMBTheOptimalAmountofInformationMoreinformationisbetterthanlessGatheringinformationhasacostMarginalbenefitstartshigh,thenfallsrapidlyLow-HangingFruitPrincipleMarginalcoststartslow,then

increasesOptimalamountofinformation

isI*whereMC=MBMCI*OptimalFreeRiderProblemAfree-riderproblemexistswhennon-payerscannotbeexcludedfromconsumingagoodInterfereswithincentivesMarketquantityisbelowsocialoptimumStoresbearthecostoftrainingsalesrepsonmerchandiseShoppersusesalesrepsasinformationsourceThensomeshoppersbuyelsewhereStoreisunabletocapturesomeofthevalueitdeliveredtotheshopper:afree-riderproblemTheLastBookstoreIndependentbookstoresdifferentiatethemselveswithpersonalizedserviceOffermoreinformationandrecommendationsthanBarnes&NoblesorBordersChainbookstorescarrylargeinventoryandshoppingcenterlocationcanerodelocalstorebaseEcommercesitessuchasAmazonandOverstockofferreviewsandrecommendationsLargeinventory;quickdeliveryOnlinesalesfurtherreducesalesinindependentstoresRationalSearchGuidelinesAdditionalsearchtimeismorelikelytobeworthwhileforexpensiveitemsthancheaponesApartmentsearchinParis,TexasinvolveslesstimethanParis,FranceTexashaslowerrentsandnarrowerpricerangePricespaidwillbehigherwhenthecostofasearchishigherTwobuyers,onlyonewithacarBuyerwiththecarwilllookatmorepianosbeforebuyingGambleInherentinSearchAdditionalsearchhascoststhatarecertainBenefitsareuncertainbenefitsAdditionalsearchhaselementsofagambleAgamblehasanumberofpossibleoutcomesEachoutcomehasaprobabilitythatitwilloccurGambleInherentinSearchTheexpectedvalueofagambleisthesumof(thepossibleoutcomestimestheirrespectiveprobability)AfairgamblehasanexpectedvalueofzeroAbetter-than-fairgamblehasapositiveexpectedvalueRiskPreferencesArisk-neutralpersonwouldacceptanygamblethatisfairorbetter-than-fairArisk-aversepersonwouldrefuseanyfairgambleSanFranciscoApartmentSearchYouneedaone-monthsubletinSanFranciscoOnetypeofapartmentrentsfor$400anditis80%oftheavailablemarketTheothertyperentsfor$360andmakesup20%ofthemarketYoumustvisittheapartmenttogettherentalrateCostpervisitis$6Youarerisk-neutralSanFranciscoApartmentSearchThefirstapartmentyouvisitisthe$400versionLookatthenextapartmentifthegambleisatleastfairTwooutcomestothegambleYoufindalower-pricedapartmentandyournetbenefitis$34with20%probabilityYoufindanother$400apartmentandyournetbenefitis–$6with80%probabilityExpectedvalueofthegambleis(34)(0.20)+(–6)(0.80)=$2KeepsearchingCommitmentProblemsandSearchSomesearchesareforcircumstancesrequiringcommitmentoversomeperiodoftimeLeasinganapartmentTakingajobGettingmarriedSearchiscostlyandthereforelimitedPeopleendtheirsearcheswhenthemarginalcostofsearchingexceedsthemarginalbenefitBUT…whatifyoufallintoabetteroption?CommitmentProblemsandSearchIfinformationwerefreelyavailable,therewouldbenocommitmentproblemContractsareusedtobindpartiestogetherANDContractscarrypenaltiesforbreakingthearrangementPeopleterminatetheirsearchbecauseinformationgatheringiscostlyUndersomecircumstances,onepartymayrationallychoosetoterminatetheagreementandpaythepenaltiesAsymmetricInformationAsymmetricinformationoccurswheneitherthebuyerorsellerIsbetterinformedaboutthegoodsinthemarketMutuallybeneficialtrades

maynotoccurAsellermightknowthat

amurderwascommittedina

houseofferedforsaleBuyerdoesnotknowPrivateSaleofaUsedCarJane'sMiataisinexcellentconditionJane'sreservationpriceis$10,000BlueBookvalueis$8,000TomwantstobuyaMiataHisreservationpriceis$13,000foroneinexcellentconditionand$9,000foroneinaverageconditionDeterminingtheconditionofJane'scarhasacostandtheresultsareuncertainTomcannotverifythatJane'sMiataissuperiorTombuysanotherMiatafor$8,000;Jane'sisunsoldSurplusLossandAsymmetricInformationTom'slossis$1,000Pays$8,000andhasagainof$1,000Tom’slossfrombuyinganaveragecarinsteadofJane's$13,000–$11,000=$2,000Tom'snetlossis$1,000Jane’slossfromlosingTomasacustomeris$1,000Totallossis$2,000TheLemonsModelPeoplewhohavebelowaveragecars(lemons),aremorelikelytowanttosellthemBuyersknowthatbelowaveragecarsarelikelytobeonthemarketandlowertheirreservationpricesGoodqualitycarsarewithdrawnfromthemarketAveragequalitydecreasesfurtherandreservationpricesdecreaseagainThelemonsmodelsaysthatasymmetricinformationtendstoreducetheaveragequalityofgoodsforsaleYourAunt'sCarYourauntoffersyouher4-yearoldAccordTheaskingpriceof$10,000isthebluebookvalueYoubelievethecarisingoodconditionBluebookvalueistheequilibriumpriceforbelowaveragecarsYoushouldbuythecarfor$10,000ItisinbetterconditionthantheaverageAccordofthesamevintageandmileageNa?veBuyerTwokindsofcars:goodcarsandlemonsOwnersknowwhatkindtheyhaveBuyerscan'tdetermineacar'squalityBuyersareriskneutralWhatwouldthebuyerofferforausedcar?Expectedvalueofacaris(0.90)($10,000)+(0.10)($6,000)=$9,600ThebuyergetsalemonGoodCarsLemonsProbability90%10%Value$10,000$6,000CredibilityProblemPartiesgainiftheyfindawaytocommunicateinformationtruthfullyIfJanecanconvinceTomherMiataisinexcellentcondition,TomwillbuyStatementsarenotcredibleJaneoffersTomasix-monthwarrantyonallcardefectsatthetimeofpurchaseAwarrantyforalemonwouldcostmorethantheeconomicsurplusgainedOnlysellersofgoodqualitycarswouldofferthewarrantyTheCostly-to-FakePrincipleTocommunicateinformationcredibly,asignalmustbecostlyordifficulttofakeSellershaveanincentivetoexaggeratethequalityoftheirproductBuyersvalueobjectiveinformationaboutqualityCostlySignalsTelevisionadvertisingisexpensiveInprintadvertising,"AsseenonTV"signalsacompany'scommitmenttoitsproductPotentialsignalofqualityEducationalinstitutions'brandsandstudents'gradessignalqualityAnA+studentfromMITismorelikelytobeofferedajobthanaCstudentfromanaverageacademicinstitutionConspicuousConsumptionChoosealawyerLawyerAwearsinexpensivesuitsanddrivesa

10-yearoldDodgeNeonLawyerBwearscustom-tailoredsuitsanddrivesanewBMW745iNootherinformationisavailableConspicuousconsumptionsignalssuccessChooseLawyerB….…andpassonBenMatlock!StatisticalDiscriminationStatisticaldiscriminationusesgroupcharacteristicstoinferindividualcharacteristicsCanbeappliedtopeopleaswellastogoodsandservicesResultsfromobserveddifferencesbetweengroupsExampleThiscandidateforemploymentisinherlatetwentiesWomenhavebabiesintheirlatetwentiesThiscandidatewillhaveababyinthenextfewyearsHighcostcomparedtoothercandidatesDangerousDriversMenunder25yearsofagepaymorethanotherdriversforautoinsuranceExpectedcostofinsuringadriverdependstheprobabilityandsizeofclaimsIndividualassessmentsarenotpossibleRatesarebasedondemographicgroupsandtheclaimhistoryofthosegroupsIndividualratesareadjustedupwardasmoreinformationbecomesavailableAdverseSelectionAdverseselectionoccursbecauseinsurancetendstobepurchasedmorebythosewhoaremostcostlyforcompaniestoinsureInsuranceismostvaluabletothosewithmanyclaimsAdverseselectionincreasesinsurancepremiumsReducesattractivenessofinsurancetolow-riskcustomers"Best"insuranceriskcustomersoptoutRatesincreaseRepeatMoralHazardMoralhazardisthetendencyofpeopletoexpendlesseffortprotectinginsuredgoodsPeopletakemoreriskwithinsuredgoodsoractivitiesDeductiblesgivepolicyholdersanincentivetobemorecautiousSupposeacarownerhasa$1,000deductiblepolicyTheownerpaysthefirst$1,000ofeachclaimStrongincentivetoavoidaccidentsClaimslessthan$1,000arenotreportedInsurancepremiumsgodownDisappearingPoliticalDiscourseDisappearingpoliticaldiscoursetheoryholdsthatpoliticianswhosupportapolicywillremainsilenttoavoidbeingmisunderstoodOpposingthedeathpenaltycouldbeinterpretedvyvotersasbeingsoftoncrimeNonecessaryrelationshipbetweenthetwoAssumesvotersimplicitlyassignapositiontoapoliticianwhohasnotmadepublicstatementsPoliticiansandtheDeathPenaltyArgumentsagainstthedeathpenaltyExpensiverelativetolifeinprisonwithoutparoleIrreversibleforpeoplelaterfoundinnocentDoesnotdetercapitalcrimesPoliticiansavoidtakingapublicpositiononcapitalpunishmentPoliticiansandtheDeathPenaltyVoterswantpoliticiansaretoughoncrimeBroaderissuethanthedeathpenaltyTwogroupsofpoliticians:toughoncrimeandsoftoncrimeVotersuseinformationaboutapolitician'sviewsonthedeathpenaltytoinferthepolitician's