曼昆 宏观经济学6

CHAPTERSIXUnemploymentslide1ChapterobjectivesThenaturalrateofunemployment:whatitmeanswhatcausesitunderstandingitsbehaviorintherealworldslide2U.S.Unemployment,1958-2002NaturalRateofUnemploymentNaturalrateofunemployment:

theaveragerateofunemploymentaroundwhichtheeconomyfluctuates.Inarecession,theactualunemploymentraterisesabovethenaturalrate.Inaboom,theactualunemploymentratefallsbelowthenaturalrate.slide4AfirstmodelofthenaturalrateNotation:

L=#ofworkersinlaborforce

E=#ofemployedworkers U=#ofunemployed U/L=unemploymentrateslide5Assumptions:1. Lisexogenouslyfixed.2. Duringanygivenmonth,

s=fractionofemployedworkers

thatbecomeseparatedfromtheirjobs,

f

=fractionofunemployedworkers

thatfindjobs.s=rateofjobseparationsf

=rateofjobfinding(bothexogenous)slide6ThetransitionsbetweenemploymentandunemploymentEmployedUnemployedfUsEslide7ThesteadystateconditionDefinition:thelabormarketisin

steadystate,orlong-runequilibrium,

iftheunemploymentrateisconstant.Thesteady-stateconditionis:s

E

=

fU#ofemployedpeoplewholoseorleavetheirjobs#ofunemployedpeoplewhofindjobsslide8Solvingforthe“equilibrium”Urate

fU =

s

E

=

s

(L–U)

=

s

L–

s

USolveforU/L:

(f+s)U

=s

Lso,slide9Example:Eachmonth,1%ofemployedworkerslosetheirjobs(s=0.01)Eachmonth,19%ofunemployedworkersfindjobs(f=0.19)Findthenaturalrateofunemployment:slide10policyimplicationApolicythataimstoreducethenaturalrateofunemploymentwillsucceedonlyifitlowerssorincreasesf.slide11Whyisthereunemployment?Ifjobfindingwereinstantaneous(f=1),

thenallspellsofunemploymentwouldbebrief,andthenaturalratewouldbe

nearzero.Therearetworeasonswhyf<1:

1.jobsearch

2.wagerigidityslide12JobSearch&FrictionalUnemploymentfrictionalunemployment:causedbythetimeittakesworkerstosearchforajoboccursevenwhenwagesareflexibleandthereareenoughjobstogoaroundoccursbecauseworkershavedifferentabilities,preferencesjobshavedifferentskillrequirementsgeographicmobilityofworkersnotinstantaneousflowofinformationaboutvacanciesandjobcandidatesisimperfectslide13Sectoralshiftsdef:changesinthecompositionofdemandamongindustriesorregionsexample:Technologicalchange

increasesdemandforcomputerrepairpersons,decreasesdemandfortypewriterrepairpersonsexample:Anewinternationaltradeagreementcausesgreaterdemandforworkersintheexportsectorsandlessdemandforworkersinimport-competingsectors.Ittakestimeforworkerstochangesectors,

sosectoralshiftscausefrictionalunemployment.slide14IndustrysharesinU.S.GDP,1960slide15IndustrysharesinU.S.GDP,1997slide16Sectoralshiftsaboundmoreexamples:Late1800s:declineofagriculture,increaseinmanufacturingLate1900s:relativedeclineofmanufacturing,increaseinservicesector1970senergycrisiscausedashiftindemandawayfromhugegasguzzlerstowardsmallercars.Inourdynamiceconomy,smaller(thoughstill

significant)sectoralshiftsoccurfrequently,

contributingtofrictionalunemployment.PublicPolicyandJobSearchGovernmentprogramsaffectunemploymentGovernmentemploymentagencies:

disseminateinformationaboutjobopeningstobettermatchworkers&jobsPublicjobtrainingprograms:

helpworkersdisplacedfromdecliningindustriesgetskillsneededforjobsingrowingindustriesUIpayspartofaworker’sformerwagesforalimitedtimeafterlosinghis/herjob.UIincreasessearchunemployment,becauseit:reducestheopportunitycostofbeingunemployedreducestheurgencyoffindingworkhence,reducesfStudies:ThelongeraworkeriseligibleforUI,

thelongerthedurationoftheaveragespellofunemployment.Unemploymentinsurance(UI)Byallowingworkersmoretimetosearch, UImayleadtobettermatchesbetween

jobsandworkers, whichwouldleadtogreaterproductivityandhigherincomes.BenefitsofUIslide20Whyisthereunemployment?Therearetworeasonswhyf<1: 1.jobsearch 2.wagerigidityDONE

Next

slide21UnemploymentfromrealwagerigidityLaborRealwageSupplyDemandUnemploymentRigid

real

wageAmountoflaborwillingtoworkAmountof

laborhiredIftherealwageisstuckabovetheequilibriumlevel,thentherearen’tenoughjobstogoaround.slide22UnemploymentfromrealwagerigidityIftherealwageisstuckabovetheequilibriumlevel,thentherearen’tenoughjobstogoaround.Then,firmsmustrationthescarcejobsamongworkers.Structuralunemployment:theunemploymentresultingfromrealwagerigidityand

jobrationing.slide23Reasonsforwagerigidity1. Minimumwagelaws2. Laborunions3. Efficiencywagesslide24TheminimumwageTheminimumwageiswellbelowtheequilibriumwageformostworkers,soitcannotexplainthemajorityofnaturalrateunemployment.However,theminimumwagemayexceedtheequilibriumwageofunskilledworkers,especiallyteenagers.Ifso,thenwewouldexpectthatincreaseintheminimumwagewouldincreaseunemploymentamongthesegroups.slide25Theminimumwageintherealworld:InSept1996,theminimumwagewasraised

from$4.25to$4.75.Here’swhathappened:Unemploymentrates,before&after3rdQ19961stQ1997Teenagers16.6%17.0%Singlemothers8.5%9.1%Allworkers5.3%5.5%Otherstudies:A10%increaseintheminimumwageincreasesteenageunemploymentby1-3%.slide26LaborunionsUnionsexercisemonopolypowertosecurehigherwagesfortheirmembers.Whentheunionwageexceedstheequilibriumwage,unemploymentresults.Employedunionworkersareinsiderswhoseinterestistokeepwageshigh.Unemployednon-unionworkersareoutsidersandwouldpreferwagestobelower(sothatlabordemandwouldbehighenoughforthemtogetjobs).EfficiencyWageTheoryTheoriesinwhichhighwagesincreaseworkerproductivity:attracthigherqualityjobapplicantsincreaseworkereffortandreduce“shirking”reduceturnover,whichiscostlyimprovehealthofworkers

(indevelopingcountries)Theincreasedproductivityjustifiesthecostofpayingabove-equilibriumwages.Theresult:unemploymentslide27slide28QuestionforDiscussion:Usethematerialwe’vejustcoveredtocomeupwithapolicyorpolicies

totrytoreducethenaturalrateofunemployment.Notewhetheryourpolicytargetsfrictionalorstructuralunemployment.slide29ThedurationofunemploymentThedata:Morespellsofunemploymentareshort-termthanmedium-termorlong-term.Yet,mostofthetotaltimespentunemployedisattributabletothelong-termunemployed.Thislong-termunemploymentisprobablystructuraland/orduetosectoralshiftsamongvastlydifferentindustries.Knowingthisisimportantbecauseitcanhelpuscraftpoliciesthataremorelikelytosucceed.slide30ThedurationofU.S.unemployment,

average,Jan1960–June2009#ofweeksunemployed#ofunemployedpersonsingroup

(%ofall

unemployedpersons)timespentunemployed

bythisgroup

(%oftimespentunemployed

byallgroups)1-442%8.1%5-1430%21.5%15ormore27%70.4%slide31TREND:Thenaturalraterisesover1960-1984,thenfallsover1985-2005Percentoflaborforceslide32EXPLAININGTHETREND:

TheminimumwageDollarsperhour$0$1$2$3$4$5$6$7$8$91950195519601965197019751980198519901995200020052010minimumwageincurrentdollarsminimumwagein2009dollarsTherealminimumwageandnaturalu-ratehavesimilartrends.slide33EXPLAININGTHETREND:

UnionmembershipSincetheearly1980s,thenaturalrateofunemploymentandunionmembershiphavebothfallen.But,from1950s

toabout1980,

thenaturalraterosewhileunionmembershipfell.Unionmembership

selectedyearsyearpercentoflaborforce193012%194535%195435%197027%198320.1%200113.5%slide34Sincemid-1980s,

oilpriceslessvolatile,sofewersectoralshifts.EXPLAININGTHETREND:

Sectoralshiftsslide35EXPLAININGTHETREND:Demographics1970s:

TheBabyBoomerswereyoung.

Youngworkerschangejobsmorefrequently(highvalueofs).Late1980sthroughtoday:

BabyBoomersaged.Middle-agedworkerschangejobslessoften(lows).

slide36TheriseinEuropeanUnemployment024681012slide37UnemploymentinEurope,1960-2008Percentoflaborforceslide38TheriseinEuropeanUnemploymentTwoexplanations:1. MostcountriesinEuropehavegeneroussocialinsuranceprograms.2. Shiftindemandfromunskilledtoskilledworkers,duetotechnologicalchange.ThisdemandshiftoccurredintheU.S.,too.Butwagerigidityislessofaproblemhere,

sotheshiftcausedanincreaseintheskilled-

to-unskilledwagegapinsteadofanincreaseinunemployment.slide39Chaptersummary