宏观经济学ch9

slide0 Chapterobjectives Thenaturalrateofunemployment whatitmeanswhatcausesitunderstandingitsbehaviorintherealworld NaturalRateofUnemployment Naturalrateofunemployment theaveragerateofunemploymentaroundwhichtheeconomyfluctuates Inarecession theactualunemploymentraterisesabovethenaturalrate Inaboom theactualunemploymentratefallsbelowthenaturalrate slide2 U S Unemployment 1958 2002 slide3 Afirstmodelofthenaturalrate Notation L ofworkersinlaborforceE ofemployedworkersU ofunemployedU L unemploymentrate slide4 Assumptions 1 Lisexogenouslyfixed 2 Duringanygivenmonth s fractionofemployedworkersthatbecomeseparatedfromtheirjobs f fractionofunemployedworkersthatfindjobs s rateofjobseparationsf rateofjobfinding bothexogenous slide5 Thetransitionsbetweenemploymentandunemployment Employed Unemployed slide6 Thesteadystatecondition Definition thelabormarketisinsteadystate orlong runequilibrium iftheunemploymentrateisconstant Thesteady stateconditionis s E f U ofemployedpeoplewholoseorleavetheirjobs ofunemployedpeoplewhofindjobs slide7 Solvingforthe equilibrium Urate f U s E s L U s L s USolveforU L f s U s Lso slide8 Example Eachmonth 1 ofemployedworkerslosetheirjobs s 0 01 Eachmonth 19 ofunemployedworkersfindjobs f 0 19 Findthenaturalrateofunemployment slide9 policyimplication Apolicythataimstoreducethenaturalrateofunemploymentwillsucceedonlyifitlowerssorincreasesf slide10 Whyisthereunemployment Ifjobfindingwereinstantaneous f 1 thenallspellsofunemploymentwouldbebrief andthenaturalratewouldbenearzero Therearetworeasonswhyf 1 1 jobsearch2 wagerigidity slide11 JobSearch FrictionalUnemployment frictionalunemployment causedbythetimeittakesworkerstosearchforajoboccursevenwhenwagesareflexibleandthereareenoughjobstogoaroundoccursbecauseworkershavedifferentabilities preferencesjobshavedifferentskillrequirementsgeographicmobilityofworkersnotinstantaneousflowofinformationaboutvacanciesandjobcandidatesisimperfect slide12 Sectoralshifts def changesinthecompositionofdemandamongindustriesorregionsexample Technologicalchangeincreasesdemandforcomputerrepairpersons decreasesdemandfortypewriterrepairpersonsexample Anewinternationaltradeagreementcausesgreaterdemandforworkersintheexportsectorsandlessdemandforworkersinimport competingsectors Ittakestimeforworkerstochangesectors sosectoralshiftscausefrictionalunemployment slide13 IndustrysharesinU S GDP 1960 slide14 IndustrysharesinU S GDP 1997 slide15 Sectoralshiftsabound moreexamples Late1800s declineofagriculture increaseinmanufacturingLate1900s relativedeclineofmanufacturing increaseinservicesector1970senergycrisiscausedashiftindemandawayfromhugegasguzzlers 酒鬼 大吃大喝的人 towardsmallercars Inourdynamiceconomy smaller thoughstillsignificant sectoralshiftsoccurfrequently contributingtofrictionalunemployment PublicPolicyandJobSearch GovtprogramsaffectingunemploymentGovtemploymentagencies disseminate 传播 infoaboutjobopeningstobettermatchworkers jobsPublicjobtrainingprograms helpworkersdisplacedfromdecliningindustriesgetskillsneededforjobsingrowingindustries UIpayspartofaworker sformerwagesforalimitedtimeafterlosinghis herjob UIincreasessearchunemployment becauseit reducestheopportunitycostofbeingunemployedreducestheurgency 紧急 迫切 offindingworkhence reducesfStudies Thelongeraworkeriseligible 合格的 forUI thelongerthedurationoftheaveragespellofunemployment Unemploymentinsurance UI Byallowingworkersmoretimetosearch UImayleadtobettermatchesbetweenjobsandworkers whichwouldleadtogreaterproductivityandhigherincomes BenefitsofUI slide19 Whyisthereunemployment Therearetworeasonswhyf 1 1 jobsearch2 wagerigidity DONE Next slide20 Unemploymentfromrealwagerigidity Iftherealwageisstuckabovetheeq mlevel thentherearen tenoughjobstogoaround slide21 Unemploymentfromrealwagerigidity Iftherealwageisstuckabovetheeq mlevel thentherearen tenoughjobstogoaround Then firmsmustrationthescarcejobsamongworkers Structuralunemployment theunemploymentresultingfromrealwagerigidityandjobrationing slide22 Reasonsforwagerigidity 1 Minimumwagelaws2 Laborunions3 Efficiencywages slide23 Theminimumwage Theminimumwageiswellbelowtheeq mwageformostworkers soitcannotexplainthemajorityofnaturalrateunemployment However theminimumwagemayexceedtheeq mwageofunskilledworkers especiallyteenagers Ifso thenwewouldexpectthatincreasesintheminimumwagewouldincreaseunemploymentamongthesegroups slide24 Theminimumwageintherealworld InSept1996 theminimumwagewasraisedfrom 4 25to 4 75 Here swhathappened Otherstudies A10 increaseintheminimumwageincreasesteenageunemploymentby1 3 slide25 Laborunions Unionsexercisemonopolypowertosecurehigherwagesfortheirmembers Whentheunionwageexceedstheeq mwage unemploymentresults Employedunionworkersareinsiderswhoseinterestistokeepwageshigh Unemployednon unionworkersareoutsidersandwouldpreferwagestobelower sothatlabordemandwouldbehighenoughforthemtogetjobs Unionmembershipandwageratiosbyindustry 2001 RBU nonunionworkersrepresentedbyaunionwageratio 100 union RBUwage nonunionwage slide26 EfficiencyWageTheory Theoriesinwhichhighwagesincreaseworkerproductivity attracthigherqualityjobapplicantsincreaseworkereffortandreduce shirking reduceturnover whichiscostlyimprovehealthofworkers indevelopingcountries Theincreasedproductivityjustifiesthecostofpayingabove equilibriumwages Theresult unemployment slide27 slide28 QuestionforDiscussion Usethematerialwe vejustcoveredtocomeupwithapolicyorpoliciestotrytoreducethenaturalrateofunemployment Notewhetheryourpolicytargetsfrictionalorstructuralunemployment slide29 ThedurationofU S unemployment averageover1993 2002 slide30 Thedurationofunemployment Thedata Morespellsofunemploymentareshort termthanmedium termorlong term Yet mostofthetotaltimespentunemployedisattributabletothelong termunemployed Thislong termunemploymentisprobablystructuraland orduetosectoralshiftsamongvastlydifferentindustries Knowingthisisimportantbecauseitcanhelpuscraftpoliciesthataremorelikelytosucceed slide31 Actual naturalratesofunemploymentintheU S slide32 EXPLAININGTHETREND Theminimumwage Thetrendintherealminimumwageissimilartothebehaviorofthenaturalrateofunemployment slide33 EXPLAININGTHETREND Unionmembership Sincetheearly1980s thenaturalrateofunemploy mentandunionmembershiphavebothfallen But from1950stoabout1980 thenaturalraterosewhileunionmembershipfell slide34 Sincemid 1980s oilpriceslessvolatile sofewersectoralshifts EXPLAININGTHETREND Sectoralshifts slide35 EXPLAININGTHETREND Demographics 1970s TheBabyBoomerswereyoung Youngworkerschangejobsmorefrequently highvalueofs Late1980sthroughtoday BabyBoomersaged Middle agedworkerschangejobslessoften lows slide36 TheriseinEuropeanUnemployment 0 2 4 6 8 10 12 slide37 TheriseinEuropeanUnemployment Twoexplanations 1 MostcountriesinEuropehavegeneroussocialinsuranceprograms 2 Shiftindemandfromunskilledtoskilledworkers duetotechnologicalchange ThisdemandshiftoccurredintheU S too Butwagerigidityislessofaproblemhere sotheshiftcausedanincreaseintheskilled to unskilledwagegapinsteadofanincreaseinunemployment slide38 Chaptersummary 1 Thenaturalrateofunemploymentthelong runaverageor steadystate rateofunemploymentdep