princ-ch20-presentation6e mankiw_6版微观经济学部分12-22章完整(全英文).ppt

N GregoryMankiw 20 Inthischapter lookfortheanswerstothesequestions Howmuchinequalityandpovertyexistinoursociety Whataretheproblemsmeasuringinequality Whataresomeoftheleadingphilosophiesontheproperroleofgovernmentinalteringthedistributionofincome Whatpoliciesareusedtofightpoverty Whataretheproblemswiththesepolicies Introduction Fromtheprevioustwochapters Equilibriumwagesequalthevalueofworkers marginalproducts Differencesinequilibriumwagesresultfromdifferencesinworkercharacteristics education experience talent effortjobcharacteristics extenttowhichajobispleasantandsafeSomeearningsdifferencesduetodiscrimination 0 Introduction Evenintheabsenceofdiscrimination theincomedistributioninamarketeconomymaynotbeequitableorotherwisedesirable Inthischapter weexamineindicatorsofinequalityandpovertyphilosophiesaboutincomeredistributionpoliciesdesignedtohelpthepoor 0 TheU S IncomeDistribution 2009 0 U S Inequality 1950 2009 0 Incomeshareofthetop20 dividedbyincomeshareofthebottom20 InequalityAroundtheWorld 0 Incomeshareofthetop10 dividedbyincomeshareofthebottom10 Poverty Povertyline anabsolutelevelofincomesetbythegovtforeachfamilysizebelowwhichafamilyisdeemedtobeinpovertyPovertyrate thepercentageofthepopulationwhosefamilyincomefallsbelowthepovertylineIn2009intheU S medianfamilyincome 61 082povertylineforfamilyoffour 21 954povertyrate 14 3 0 U S PovertyOverTime Percentofthepopulationbelowpovertyline 0 U S PovertyRatebyGroup 2009 0 ProblemsMeasuringInequality 1 In kindtransfers assistancethattakestheformofg sratherthancashOmittedfrommeasuresofinequalityandpoverty biasingthemupward2 TheLifeCycle theregularpatternofincomevariationoveraperson slifePeoplecanborrowandsavetooffsetlife cyclechangesinincome e g savingforretirement Life cycleincomevariationcausesinequalityinincomebutnotinequalityinlivingstandards 0 ProblemsMeasuringInequality 3 Transitoryvs PermanentIncome Peoplecanborrowandsavetosmoothouttransitoryincomefluctuations Abettermeasureofinequalityinlivingstandardswouldbebasednotoncurrentincome butonpermanentincome aperson snormalincome 4 Economicmobility Manypeoplemoveamongincomeclasses Thepovertyandinequalitymeasuresdiscussedabovedonotdistinguishbetweenthetemporarilypoorandthepersistentlypoor 0 ThePoliticalPhilosophyofRedistributingIncome Weconsiderthreephilosophies UtilitarianismLiberalismLibertarianism 0 Utilitarianism Utility ameasureofhappinessorsatisfactionUtilitarianism arguesthatgovtshouldchoosepoliciestomaximizesociety stotalutilityFounders JeremyBentham JohnStuartMillBecauseofdiminishingmarginalutility redistributingincomefromrichtopoorincreasesutilityofthepoormorethanitreducesutilityoftherich Yet utilitariansdonotadvocateequalizingincomes wouldreducetotalincomeofeveryoneduetoincentiveeffectsandefficiencylosses 0 Liberalism Liberalism arguesthatgovtshouldchoosepoliciesdeemedtobejustbyanimpartialobserverbehinda veilofignorance Founder JohnRawlsMaximincriterion govtshouldaimtomaximizethewell beingofsociety sworst offpersonCallsformoreredistributionthanutilitarianism thoughstillnotcompleteequalizationofincomes Incomeredistributionisaformofsocialinsurance agovtpolicyaimedatprotectingpeopleagainsttheriskofadverseevents 0 Libertarianism Libertarianism arguesthatgovtshouldpunishcrimesandenforcevoluntaryagreementsbutnotredistributeincomeAdvocate RobertNozickInsteadoffocusingonoutcomes libertariansfocusontheprocess Govtshouldenforceindividualrights shouldtrytoequalizeopportunities Iftheincomedistributionisachievedfairly govtshouldnotinterfere evenifunequal 0 PoliciestoReducePoverty PoorfamiliesmorelikelytoexperiencehomelessnessdrugdependencehealthproblemsteenpregnancyilliteracyunemploymentMostpeoplebelievegovtshouldprovidea safetynet Wenowconsiderafewsuchpolicies 0 1 Minimum WageLaws Argumentsfor Helpsthepoorwithoutanycosttothegovt Littleimpactonemploymentifdemandforunskilledlaborisrelativelyinelastic Argumentsagainst Inthelongrun demandforunskilledlaborislikelyelastic sominimumwagecausessubstantialunemploymentamongtheunskilled Thosehelpedbyminimumwagearemorelikelytobeteensfrommiddle incomefamiliesthanlow incomeadultworkers 0 2 Welfare Welfare govtprogramsthatsupplementtheincomesoftheneedyTemporaryAssistanceforNeedyFamilies TANF SupplementalSecurityIncome SSI Criticsarguethatsuchprogramscreateincentivestobecomeorremainneedy arguethatwelfarecontributedtotheriseofthesingle parentfamily However theseverityofsuchincentiveproblemsisunknown Proponentsnotethatinflation adjustedwelfarebenefitsfellassingle parentfamiliesincreased 0 3 NegativeIncomeTax Negativeincometax ataxsystemthatcollectsrevenuefromhigh incomehouseholdsandgivestransferstolow incomehouseholdsExample Taxesowed 1 3ofincome 10 000Ifearnings 90 000 taxesowed 20 000Ifearnings 60 000 taxesowed 10 000Ifearnings 30 000 taxesowed 0Ifearnings 15 000 taxes owed 5 000i e wouldreceive 5 000paymentfromgovtTheEarnedIncomeTaxCredit EITC issimilartoanegativeincometax 0 4 In KindTransfers In kindtransfersaregoodsorservicesprovidedtotheneedy Examples homelessshelterssoupkitchensfoodstamps govtvouchersredeemableforfoodatgrocerystoresMedicaid govt providedhealthcareforthepoorAnalternative cashpaymentswouldallowpeopletobuywhattheymostneedbutcriticsarguecouldbeusedfordrugs alcohol 0 Anti PovertyProgramsandWorkIncentives Assistancefromanti povertyprogramsdeclinesasincomerises Theresult Poorfamiliesfacehigheffectivemarginaltaxrates exceeding100 insomecases Suchpoliciesthereforediscouragethepoorfromescapingpovertyontheirown Onepossiblesolution Workfare asystemrequiringpeopletoacceptgovernmentjobswhilecollectingbenefits 0 CONCLUSION Povertyisoneofsociety smostseriousproblems OneoftheTenPrinciplesfromChapter1 Governmentscansometimesimprovemarketoutcomes Publicpolicycanhelpreducepovertyandinequality Anotherprinciple Peoplefacetrade offs Policiesdesignedtoimproveequityoftensacrificeefficiency sotheproperscopeofpolicyisthesubjectofongoingcontroversy 0 SUMMARY Dataonincomedistributionshowawidedisparityinoursociety Therichest20 offamiliesearnabouttentimesasmuchasthepoorest20 Problemsinmeasuringinequalityarisefromin kindtransfers theeconomiclifecycle transitoryincome andeconomicmobility Whenthesefactorsaretakenintoaccount thedistributionofwell beingisprobablylessunequalthanthedistributionofannualincome 2012CengageLearning AllRightsReserved Maynotbecopied scanned orduplicated inwholeorinpart exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword protectedwebsiteforclassroomuse SUMMARY Politicalphilosophersdifferintheirviewsoftheproperroleofgovernmentinalteringtheincomedistribution Utilitariansbelievethatincomedistributionshouldmaximizethesumofeveryone sutility Liberalsbelievethegovernmentshouldaimtomaximizethewell beingoftheworst offpersoninsociety Libertariansbelievethegovernment