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

1、,N.GregoryMankiw,20,Inthischapter,lookfortheanswerstothesequestions:,Howmuchinequalityandpovertyexistinoursociety?Whataretheproblemsmeasuringinequality?Whataresomeoftheleadingphilosophiesontheproperroleofgovernmentinalteringthedistributionofincome?Whatpoliciesareusedtofightpoverty?Whataretheproblems

2、withthesepolicies?,Introduction,Fromtheprevioustwochapters:Equilibriumwagesequalthevalueofworkersmarginalproducts.Differencesinequilibriumwagesresultfromdifferencesinworkercharacteristics:education,experience,talent,effortjobcharacteristics:extenttowhichajobispleasantandsafeSomeearningsdifferencesdu

3、etodiscrimination.,0,Introduction,Evenintheabsenceofdiscrimination,theincomedistributioninamarketeconomymaynotbeequitableorotherwisedesirable.Inthischapter,weexamineindicatorsofinequalityandpovertyphilosophiesaboutincomeredistributionpoliciesdesignedtohelpthepoor,0,TheU.S.IncomeDistribution:2009,0,U

4、.S.Inequality,19502009,0,Incomeshareofthetop20%dividedbyincomeshareofthebottom20%,InequalityAroundtheWorld,0,Incomeshareofthetop10%dividedbyincomeshareofthebottom10%,Poverty,Povertyline:anabsolutelevelofincomesetbythegovtforeachfamilysizebelowwhichafamilyisdeemedtobeinpovertyPovertyrate:thepercentag

5、eofthepopulationwhosefamilyincomefallsbelowthepovertylineIn2009intheU.S.,medianfamilyincome=$61,082povertylineforfamilyoffour=$21,954povertyrate=14.3%,0,U.S.PovertyOverTime,Percentofthepopulationbelowpovertyline,0,U.S.PovertyRatebyGroup,2009,0,ProblemsMeasuringInequality,1.In-kindtransfers:assistanc

6、ethattakestheformofg&sratherthancashOmittedfrommeasuresofinequalityandpoverty,biasingthemupward2.TheLifeCycle:theregularpatternofincomevariationoverapersonslifePeoplecanborrowandsavetooffsetlife-cyclechangesinincome(e.g.,savingforretirement).Life-cycleincomevariationcausesinequalityinincomebutnotine

7、qualityinlivingstandards.,0,ProblemsMeasuringInequality,3.Transitoryvs.PermanentIncome:Peoplecanborrowandsavetosmoothouttransitoryincomefluctuations.Abettermeasureofinequalityinlivingstandardswouldbebasednotoncurrentincome,butonpermanentincome,apersonsnormalincome.4.Economicmobility:Manypeoplemoveam

8、ongincomeclasses.Thepovertyandinequalitymeasuresdiscussedabovedonotdistinguishbetweenthetemporarilypoorandthepersistentlypoor.,0,ThePoliticalPhilosophyofRedistributingIncome,Weconsiderthreephilosophies:UtilitarianismLiberalismLibertarianism,0,Utilitarianism,Utility:ameasureofhappinessorsatisfactionU

9、tilitarianism:arguesthatgovtshouldchoosepoliciestomaximizesocietystotalutilityFounders:JeremyBentham,JohnStuartMillBecauseofdiminishingmarginalutility,redistributingincomefromrichtopoorincreasesutilityofthepoormorethanitreducesutilityoftherich.Yet,utilitariansdonotadvocateequalizingincomeswouldreduc

10、etotalincomeofeveryoneduetoincentiveeffectsandefficiencylosses.,0,Liberalism,Liberalism:arguesthatgovtshouldchoosepoliciesdeemedtobejustbyanimpartialobserverbehinda“veilofignorance”Founder:JohnRawlsMaximincriterion:govtshouldaimtomaximizethewell-beingofsocietysworst-offpersonCallsformoreredistributi

11、onthanutilitarianism(thoughstillnotcompleteequalizationofincomes).Incomeredistributionisaformofsocialinsurance,agovtpolicyaimedatprotectingpeopleagainsttheriskofadverseevents.,0,Libertarianism,Libertarianism:arguesthatgovtshouldpunishcrimesandenforcevoluntaryagreementsbutnotredistributeincomeAdvocat

12、e:RobertNozickInsteadoffocusingonoutcomes,libertariansfocusontheprocess.Govtshouldenforceindividualrights,shouldtrytoequalizeopportunities.Iftheincomedistributionisachievedfairly,govtshouldnotinterfere,evenifunequal.,0,PoliciestoReducePoverty,Poorfamiliesmorelikelytoexperiencehomelessnessdrugdepende

13、ncehealthproblemsteenpregnancyilliteracyunemploymentMostpeoplebelievegovtshouldprovidea“safetynet.”Wenowconsiderafewsuchpolicies,0,1.Minimum-WageLaws,Argumentsfor:Helpsthepoorwithoutanycosttothegovt.Littleimpactonemploymentifdemandforunskilledlaborisrelativelyinelastic.Argumentsagainst:Inthelongrun,

14、demandforunskilledlaborislikelyelastic,sominimumwagecausessubstantialunemploymentamongtheunskilled.Thosehelpedbyminimumwagearemorelikelytobeteensfrommiddle-incomefamiliesthanlow-incomeadultworkers.,0,2.Welfare,Welfare:govtprogramsthatsupplementtheincomesoftheneedyTemporaryAssistanceforNeedyFamilies(

15、TANF)SupplementalSecurityIncome(SSI)Criticsarguethatsuchprogramscreateincentivestobecomeorremainneedy,arguethatwelfarecontributedtotheriseofthesingle-parentfamily.However,theseverityofsuchincentiveproblemsisunknown.Proponentsnotethatinflation-adjustedwelfarebenefitsfellassingle-parentfamiliesincreas

16、ed.,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,tax

17、es“owed”=$5,000i.e.,wouldreceive$5,000paymentfromgovtTheEarnedIncomeTaxCredit(EITC)issimilartoanegativeincometax.,0,4.In-KindTransfers,In-kindtransfersaregoodsorservicesprovidedtotheneedy.Examples:homelessshelterssoupkitchensfoodstamps,govtvouchersredeemableforfoodatgrocerystoresMedicaid,govt-provid

18、edhealthcareforthepoorAnalternative:cashpaymentswouldallowpeopletobuywhattheymostneedbutcriticsarguecouldbeusedfordrugs,alcohol,0,Anti-PovertyProgramsandWorkIncentives,Assistancefromanti-povertyprogramsdeclinesasincomerises.Theresult:Poorfamiliesfacehigheffectivemarginaltaxrates(exceeding100%insomec

19、ases!).Suchpoliciesthereforediscouragethepoorfromescapingpovertyontheirown.Onepossiblesolution:“Workfare,”asystemrequiringpeopletoacceptgovernmentjobswhilecollectingbenefits.,0,CONCLUSION,Povertyisoneofsocietysmostseriousproblems.OneoftheTenPrinciplesfromChapter1:Governmentscansometimesimprovemarket

20、outcomes.Publicpolicycanhelpreducepovertyandinequality.Anotherprinciple:Peoplefacetrade-offs.Policiesdesignedtoimproveequityoftensacrificeefficiency,sotheproperscopeofpolicyisthesubjectofongoingcontroversy.,0,SUMMARY,Dataonincomedistributionshowawidedisparityinoursociety.Therichest20%offamiliesearna

21、bouttentimesasmuchasthepoorest20%.Problemsinmeasuringinequalityarisefromin-kindtransfers,theeconomiclifecycle,transitoryincome,andeconomicmobility.Whenthesefactorsaretakenintoaccount,thedistributionofwell-beingisprobablylessunequalthanthedistributionofannualincome.,2012CengageLearning.AllRightsReser

22、ved.Maynotbecopied,scanned,orduplicated,inwholeorinpart,exceptforuseaspermittedinalicensedistributedwithacertainproductorserviceorotherwiseonapassword-protectedwebsiteforclassroomuse.,SUMMARY,Politicalphilosophersdifferintheirviewsoftheproperroleofgovernmentinalteringtheincomedistribution.Utilitariansbelievethatincomedistributionshouldmaximizethesumofeveryonesutility.Liberalsbelievethegovernmentshouldaimtomaximizethewell-beingoftheworst-offpersoninsociety.Libe