Aｎsweｒs to Textbook Questioｎｓ ａｎd Problｅms
CHAPＴＥR 7 Ｕnｅｍｐloｙment and the Laｂor Mａｒｋeｔ
Ｑｕesｔions fｏｒ Ｒeview
1.?Tｈe rａtes oｆ ｊob separaｔioｎ anｄ jｏb fｉnding dｅteｒmｉｎｅ the natｕral rａte of unemplo
ｙmeｎt. Ｔhe ｒａte of job sepaｒａtｉoｎ ｉs ｔhe fractiｏn ｏf peopｌe whｏ lose theiｒ job eacｈ ｍontｈ． The higheｒ the ｒate of joｂ seｐaration, the higheｒ ｔhｅ naｔｕraｌ ratｅ oｆ unempｌoｙmeｎｔ. Tｈｅ rａtｅ of job ｆinｄｉｎg is ｔhe fractioｎ of ｕnｅmｐloyed people ｗho fｉnd a job eaｃh ｍoｎth． The hｉｇｈｅｒ the rate oｆ ｊｏb fｉndｉｎｇ, tｈe lｏwer the natural rａte oｆ uneｍpｌoyment.
2.?Fｒicｔioｎal ｕnemployｍｅnt iｓ ｔｈe ｕｎemplｏｙｍｅｎt caused by the ｔime it taｋes to
match ｗorkｅｒs ａｎd jobｓ． Finding ａn ａpprｏｐｒiate job ｔaｋes tｉｍe because thｅ ｆlow ｏf ｉnfｏrmation ａｂoｕｔ job cａnｄidates and joｂ ｖacaｎcies ｉs not iｎstantaｎeoｕs． Ｂecaｕse different ｊobs rｅqｕire diｆferｅｎt skills and pay difｆereｎt wagｅs, uｎemｐloyｅd workeｒｓ may ｎot acｃept ｔｈe ｆirst joｂ offeｒ ｔhey receｉve． ?In conｔrast， sｔｒucｔuraｌ uneｍpｌoyment is the unemploｙmｅnｔ resulｔing fｒom ｗａ
gｅ rigidity anｄ job ｒationiｎg. Tｈesｅ workｅｒs are uneｍploｙeｄ ｎoｔ because theｙ are actiｖeｌy seａrching for a jｏb thａt best suｉｔs their skilｌs (as in tｈe ｃase of ｆriｃtional ｕneｍplｏｙmｅｎt)， ｂｕt ｂeｃauｓe aｔ the prevaｉlinｇ ｒｅａl waｇe ｔｈｅ quantｉｔy oｆ laｂor suppｌｉed eｘceeds the ｑｕantｉｔｙ of labｏｒ dｅmanｄeｄ. If thｅ waｇe ｄoes noｔ adjｕst to clear the ｌaｂor mａrket, ｔhｅn ｔheｓe ｗｏrkers ｍust wａｉt ｆｏr joｂs ｔｏ ｂecome aｖailable. Struｃｔuｒaｌ uneｍployment tｈus ariseｓ because ｆirｍｓ fail to rｅduｃe ｗaｇes ｄeｓpite an exｃesｓ supｐly ｏｆ laｂor.
3． The real ｗaｇｅ may remaiｎ above ｔｈe ｌeｖｅl ｔhａt equｉliｂrａtes labor supply and
labor demand because ｏｆ ｍinｉmum wage laws, tｈe ｍonｏｐoly poｗｅr of unioｎs， and effｉciency ｗages.
??Minimuｍ－wage ｌaws ｃaｕｓｅ wａge riｇidity wｈｅn they pｒevenｔ ｗaｇeｓ ｆrｏm falｌ
ｉng tｏ eｑｕilibrｉuｍ levels. Aｌthough mosｔ ｗorkerｓ aｒe paid a ｗage ａbove tｈe minｉmuｍ lｅvel, for ｓｏme ｗorkｅrs， espeｃｉａlly tｈｅ unskｉlｌed and inexperieｎceｄ, tｈｅ ｍinimｕm ｗａge raisｅs ｔｈｅir ｗage aboｖe the eｑuilibrｉum leveｌ. Ｉｔ tｈerefｏｒe reｄuces the quanｔity of their laboｒ tｈat firms ｄｅmand, and ｃreａtes an exceｓs supｐlｙ of wｏrkers, which incｒeasｅs unempｌoｙmenｔ. The monopoly power oｆ unions cａｕses waｇe rigidity becａuse the wageｓ of ｕniｏ
nizｅd wｏrkeｒs ａre dｅｔｅrmiｎeｄ nｏt by thｅ ｅquilibrium of suｐply ａnd dｅmand but ｂy collectｉve bａrgainｉng beｔweｅn uｎion leａdｅrs ａnd ｆirm mａnaｇemｅnt. Tｈｅ ｗagｅ ａgreｅmｅnｔ ｏftｅn raises tｈe wage above thｅ equiｌibrium level ａnd ａｌloｗs the fiｒｍ to decｉde how many woｒkers ｔo eｍplｏｙ. These ｈigh waｇeｓ cauｓｅ fｉrｍs ｔo ｈirｅ feｗer workers thａn ａｔ ｔhe mａｒket-cleａring wage, so structｕｒal unemplｏyment incｒｅａｓｅs.
??Effｉｃiｅncｙ－ｗage theｏｒiｅｓ ｓuggeｓt tｈaｔ high ｗages ｍake worｋｅrs ｍorｅ proｄ
uctｉvｅ． Tｈe influeｎce of waｇes on wｏｒkｅｒ efｆiciｅｎcy may eｘplａin why fｉrms ｄo noｔ cut wages despiｔｅ an exｃｅss sｕpplｙ ｏf labｏr. Even thｏugh a wage reｄuction dｅcreaｓｅs the fｉrm’s waｇe bｉll, it ｍaｙ also lower worｋer productivｉtｙ and therｅfore tｈe ｆirm’s profitｓ.
４.?Ｄepｅnｄing oｎ hoｗ onｅ looｋｓ ａｔ ｔhｅ data， most ｕnempｌｏyｍent can aｐpear tｏ
ｂe eithｅr ｓhｏrt tｅrm or ｌoｎg tｅrm. Most spｅｌlｓ oｆ unemployment ａre shoｒt； ｔhａt iｓ, ｍｏst of those ｗho bｅcame unｅｍpｌoｙｅd finｄ jｏｂs quicklｙ. On the other ｈａnd， most wｅeks of unemｐloｙｍent are ａｔtrｉbutaｂlｅ ｔo the smａｌl numbｅｒ of long-teｒm unｅｍｐlｏyeｄ. Bｙ deｆiｎｉｔion, thｅ ｌｏnｇ-ｔeｒｍ unempｌoｙeｄ do ｎot fiｎd jｏbs ｑuiｃklｙ, so ｔhey apｐｅaｒ on ｕnemplｏyment rｏｌls for many weｅkｓ or mｏnthｓ.
5.?Europｅans woｒk fewｅｒ hours than Ameriｃanｓ. Oｎe explaｎation iｓ ｔhａt thｅ hｉgher ｉ
ncｏme ｔax ratｅｓ in Ｅurｏｐe ｒeｄuｃe ｔｈe incentiｖｅ to worｋ. Ａ ｓeｃond expｌaｎａtioｎ is a lａrger unｄｅrground ｅconomy ｉn Euｒope ａs a reｓult of ｍoｒe pｅople attempｔing tｏ evａde thｅ ｈｉgh taｘ raｔeｓ． A third explａｎatｉon ｉs tｈｅ grｅater impｏrｔanｃe ｏｆ unions in Ｅurope anｄ their abiｌity tｏ bａrｇain for reｄuｃed wｏrｋ hours. A fｉnaｌ explanation is baｓed on prefeｒｅncｅｓ, whereby Europeans ｖalｕe lｅisuｒe ｍore ｔhａn Ａmｅricans do, anｄ ｔｈereｆore eleｃt to woｒk fewer houｒｓ.
Proｂlemｓ and Applｉｃatｉons
１.?a．?In the ｅｘaｍple that ｆollｏｗs, we ａssume thaｔ dｕｒinｇ ｔhe ｓchｏol yeaｒ you
lｏok ｆoｒ a pａrt－time job, aｎｄ that, ｏｎ aveｒage, iｔ ｔakｅｓ ２ wｅeks to fｉｎd ｏnｅ. We aｌso assｕme ｔhａｔ ｔhe typicaｌ job ｌasｔs 1 semester, or 1２ weekｓ.
b.?If it ｔakes 2 weeks ｔｏ fiｎd a jｏb, then the raｔe ｏf joｂ ｆｉnｄing in ｗeeｋs is f ＝ (1 job／2 wｅekｓ) = ０.5 jｏｂｓ/ｗeeｋ． ?Ｉｆ the job lasts for 1２ wｅeｋs, thｅn the rate of ｊｏb separatiｏn in weeｋs iｓ
?ｓ = (1 ｊob/12 ｗeeks) = 0．0８3 ｊoｂs/weｅk.
?c．?Fｒｏm tｈe text， we know thaｔ the formｕla fｏr tｈｅ ｎatｕral ｒate of unemploｙment ｉｓ (Ｕ/L) = [s/（ｓ ＋ f )], ?wheｒe U is the nuｍbｅr of ｐeople unempｌｏyeｄ， ａnd Ｌ is ｔhe numｂer of people in the labor ｆｏｒｃe. ?Plugｇing in ｔhe vａｌues fｏr f and s that were calcｕlａtｅd in pａｒt (b）, wｅ finｄ （Ｕ/Ｌ） ＝ [０.０83/(0.083 + 0．５)] = 0.１4.
?Thuｓ, ｉｆ on averａｇｅ it ｔａkes 2 ｗeeks ｔo ｆind a joｂ ｔhａｔ laｓtｓ １2 ｗeeｋs,
ｔｈe natｕｒal ｒatｅ oｆ unemplｏyment for thｉｓ populatioｎ of ｃollege stｕdentｓ seｅking paｒt-ｔime eｍplｏyｍent is 14 perｃｅnt.
2． Caｌl ｔhｅ nｕmber of reｓidｅnｔｓ oｆ ｔhe dorm whｏ arｅ iｎvolved I, the nｕmb
ｅｒ who aｒｅ uninvolｖｅｄ U, and ｔhe total nuｍｂeｒ of students T = Ｉ + U． Iｎ steady
statｅ thｅ total number of invｏlvｅd stｕdeｎts iｓ consｔａｎｔ. For tｈis tｏ happｅn we neeｄ ｔhe number oｆ newｌy unｉnvolved stｕdeｎts, （0.10)I， to be equal ｔo tｈe nｕmber of students who just ｂｅcame inｖｏｌvｅｄ, （0.05)U. Following a few substiｔutｉonｓ：
?(０.05）U ?ｓo
= (0.10)I = (0．10)（T – U),
U0.10= T0.10 + 0.052=.3 Wｅ find that tｗo-tｈｉrds of the ｓtｕdｅｎtｓ are uninvolved. ?
3. Ｔo sｈoｗ that tｈe ｕnemplｏymeｎt raｔe eｖolveｓ over time to tｈe steａdy-state
raｔe， ｌｅt’s beｇｉｎ by defining how ｔhe nuｍbeｒ ｏf pｅopｌe unemｐlｏyｅｄ ｃhanges ｏver tiｍｅ. Tｈe chａngｅ ｉn thｅ nuｍber of unemｐｌｏyed eｑuals ｔｈe number of ｐｅoplｅ losing joｂs (sE) minus the nｕmber fｉｎdinｇ jobs (ｆU). In equation ｆoｒm, ｗｅ can exprｅss this as:
?Ut + 1 – Ut = ΔUｔ + １ = sEt – fUt. Ｒecall ｆｒｏｍ tｈe teｘt tｈａt Ｌ ＝ Ｅt + Ut， or Ｅt = Ｌ – Ut， where L is the total
laｂor fｏrｃｅ （we ｗill ａｓsume thａt L ｉｓ coｎstanｔ）. Sｕbstituｔiｎg for Eｔ in thｅ above equation， we fｉｎｄ ΔUt + 1 = ｓ(Ｌ – Ut) – ｆＵｔ.
?Dividｉnｇ by Ｌ, we ｇet ａn eｘpressｉｏn for ｔhe chａnge in the ｕｎemplｏｙment rａte ｆrｏm t to t + １:
?ΔＵt ＋ 1／L = （Ut + 1/L) – (Ｕt/Ｌ） ＝ Δ[U/L]t + 1 = s(1 – Ut/L) – fＵt/Ｌ.
?Ｒｅarrangｉｎg terms oｎ tｈe ｒigｈｔ sidｅ of ｔhe equatｉｏn aboｖe, wｅ eｎｄ uｐ witｈ line 1
ｂｅlow. Noｗ take line 1 ｂelｏw, multipｌｙ ｔhe ｒiｇｈt siｄe ｂy （s ＋ f)/(s + ｆ) ａnd rearrａnｇｅ teｒms to ｅｎｄ ｕp wｉtｈ lｉｎe 2 below: Δ[U/L］t ＋ １ ＝ s – （s + f)Uｔ/Ｌ ??= （s ＋ f)[s/(s + f) – Uｔ/Ｌ]．
?The ｆirst point to notｅ about ｔhis eqｕation ｉｓ thaｔ iｎ steadｙ state, wｈen the uｎe
ｍpｌoyｍent ratｅ eqｕals its natｕral ratｅ， tｈe left-hanｄ siｄe of thiｓ expressioｎ equaｌs zeｒo. Thiｓ tells ｕs thaｔ, aｓ we found in tｈe teｘt, tｈe ｎatuｒal ｒate of ｕnｅmplｏymｅnt (Ｕ／L)ｎ equals s/（ｓ + ｆ). Ｗe ｃan now rewｒite the aｂoｖe expｒession, substｉtuting （U/L）n ｆor s／(ｓ + f）， tｏ get aｎ equａtioｎ thａt is easiｅr tｏ ｉnｔerpret:
?Δ[U／L]ｔ + 1 = （ｓ ＋ f)[（U/L)n – Ｕt/Ｌ]．
曼昆-宏观经济经济学第九版-英文原版标准答案7
