曼昆经济学原理第5版微观PPT第六章(6)免费中文版

©2009South-Western,apartofCengageLearning,allrightsreservedCHAPTER供给、需求与政府政策经济学原理N.格里高利.曼昆著6供给、需求与政府政策Thischapterbuildsontheprevioustwo(supply&demandandelasticity).StudentswholearnedthosechapterswellusuallydonothavemuchdifficultywiththematerialinChapter6.Thischaptercanusuallybecoveredinabout90minutesofclasstime.Ihavecombinedtheanalysisofpriceceilingswiththerentcontrolexample,andI’vecombinedtheanalysisofpricefloorswiththeminimumwageexample.(Incontrast,thetextbookpresentsagenericanalysisofpriceceilings,thentherentcontrolexample,thenagenericanalysisofpricefloors,thentheminimumwage).Moststudentslearnnewconceptsbetterinthecontextofaspecificexampleratherthanagenericanalysis,andcombiningtheminthiswaysavesclasstime.Here’sanideayoumightconsider:Attheendoftheclasssessionjustpriortotheoneinwhichyoubegintocoverthischapter,askstudentstotakeoutapieceofblankpaper,andwritedownwhethertheythinktheminimumwageshouldbeincreased,andtheirreason(s).Tellthemnottowritetheirnames(youwantthemtobecandid),andhavethemleavetheirpiecesofpaperinapileastheyexittheclassroom.Later,dividethepapersintotwogroupsbasedonwhethertheysupportoropposeincreasingtheminimumwage.InthisPowerPointfile,immediatelyafterthisslide,insertnewtwoslides,titlingthem“Yourreasonsforraisingtheminimumwage”and“Yourreasonsfornotraisingtheminimumwage.”Summarizeoneachslidethemostcommonreasonsstudentsgave.Begintheclasssessionbyshowingthemtheresultsofthisimpromptusurvey(howmanystudentsrespondedeachway,andthemostcommonreasons).Tellthosestudentsthatsupportaminimumwageincreasethattheirthinkingrepresentsthatofmanyeducatednon-economists.Buttellthemthateconomicsoffersanotherperspective,andthisissomethingtheywilllearninthischapter.Ifyoudothis,thenIrecommendrearrangingtheslidesabitsothatthepricefloor/minimumwageslidescomeBEFOREthepriceceiling/rentcontrolslides.供给、需求与政府政策*本教学 ppt 关于艾滋病ppt课件精益管理ppt下载地图下载ppt可编辑假如ppt教学课件下载triz基础知识ppt 双语版由浙江工商大学经济学院陈宇峰编译*供给、需求与政府政策本章我们将探索这些问题的 答案 八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案 ：什么是价格上限与价格下限？各有什么例子？价格上限与价格下限如何影响市场结果？税收如何影响市场结果？对买者还是卖者征税对市场结果有什么不同吗？什么是税收归宿？什么决定税收归宿？*Whenwetalkabouthowapolicy“affectsthemarketoutcome,”wemeanthepolicy’simpactonthepriceandquantityofthegoodandthereforeonthemarket’sallocationofresources.Theconcludingslideelaboratesonthisabit.供给、需求与政府政策*改变私人市场结果的政府政策 价格控制： 价格上限：出售一种物品或服务的法定最高价格比如：租金控制 价格下限：出售一种物品或服务的法定最低价格比如：最低工资 税收： 政府要求买者或卖者每买进或卖出一单位物品所支付的一定数量的货币我们将使用供求模型来分析各种类型的政府政策如何影响市场结果（买者支付的价格，卖者得到的价格，以及均衡数量）供给、需求与政府政策*Thisslideoutlinesthechapter.供给、需求与政府政策*例1:公寓市场没有价格控制的均衡供给、需求与政府政策*Westartbyanalyzingtheeffectsofapriceceiling.Themostcommonexampleisrentcontrol,sowedotheanalysisinthecontextofthisexample.Webeginbyshowingthemarketforapartmentsinequilibrium(beforethegovernmentimposesanypricecontrols).供给、需求与政府政策*价格上限如何影响市场结果价格上限高于均衡均衡价格时没有限制性—即对市场结果没有影响供给、需求与政府政策*Whensomestudentsseethisforthefirsttime,theywonderwhythepriceceilingdoesnotresultinasurplus.Whenthepriceceilingisabovetheequilibriumprice,theequilibriumpriceisstillperfectlylegal.Justbecauselandlordsareallowedtocharge$1000rentdoesn’tmeantheywill–iftheydo,theywon’tbeabletorentalloftheirapartments–asurpluswillresult,causingdownwardpressureontheprice(rent).There’snolawthatpreventstheprice(rent)fromfalling,soitdoesfalluntilthesurplusisgoneandequilibriumisreached(atP=$800andQ=300).供给、需求与政府政策*价格上限如何影响市场结果均衡价格（$800）高于价格上限，因此是违法的价格上限是一种限制性约束，这导致了短缺$800供给、需求与政府政策*Inthiscase,thepriceceilingisbinding.Inthenewequilibriumwiththepriceceiling,theactualprice(rent)ofanapartmentwillbe$500.Itwon’tbemorethanthat,becauseanyhigherpriceisillegal.Itwon’tbelessthan$500,becausetheshortagewouldbeevenlargerifthepricewerelower.Theactualquantityofapartmentsrentedequals250,andthereisashortageequalto150(thedifferencebetweenthequantitydemanded,400,andthequantitysupplied,250).供给、需求与政府政策*价格上限如何影响市场结果长期，供给与需求都更具有弹性。因此，短期更加严重$800150450供给、需求与政府政策*Inthisslide,theequilibriumprice($800)andpriceceiling($500)arethesameasontheprecedingslides,butsupplyanddemandaremoreprice-elasticthanbefore,andtheshortagethatresultsfromabindingpriceceilingislarger.供给、需求与政府政策*短缺与配给 面临短缺时，卖者必须在买者之间配给稀缺物品 配给机制：（1）排长队（2）根据卖者的偏好 这些配件机制既可能是不公平的，也是无效率的：因为物品并不一定会卖给对它评价最高的买者 与此相比，一个自由竞争市场中的配给机制既有效率（物品卖给对它评价最高的买者），也是客观的（就是公平的）供给、需求与政府政策*Thelasttwobulletsdiscuss“efficiency”inthecontextofrationinggoodstothosebuyerswhovaluethemmosthighly.Thisconceptwillbeexploredfurtherinthefollowingchapter.供给、需求与政府政策*例2:缺乏技能的劳动力的市场没有价格控制时的均衡供给、需求与政府政策*Nowweswitchgearsandlookattheeffectsofapricefloor.Weillustratethisconceptusingthecommontextbookexample–theminimumwage.Thismaybethefirsttimestudentshaveseenasupply-demanddiagramofthelabormarket.Itmightbeusefultonotethatthe“price”oflaborissimplythewage,whichwemeasureontheverticalaxisofoursupply-demanddiagram.Alongthehorizontalaxis,wemeasurethequantityoflabor(numberofworkers).Thedemandforunskilledlaborcomesfromfirms.Thesupplycomesfromworkers.Wefocusonunskilledlaborbecausetheminimumwageisnotrelevantforhigherskilled,higherwageworkers.供给、需求与政府政策*价格下限如何影响市场结果低于均衡价格的的价格下限没有限制性—即对市场结果没有影响供给、需求与政府政策*Somestudentsmaywonderwhythe$3pricefloordoesnotcauseashortage.Afterall,atawageof$3,thequantityofunskilledworkersthatfirmswishtohireexceedsthequantityofunskilledworkersthatarelookingforjobs.Buttheminimumwagelawdoesnotstopthewagefromrisingabove$3.So,inresponsetothisshortage,thewagewillriseuntiltheshortagedisappears–whichoccursattheequilibriumwageof$4.Theequilibriumwageisperfectlylegalwhenthepricefloor(i.e.minimumwage)isbelowit.供给、需求与政府政策*价格下限如何影响市场结果均衡价格（$4）低于价格下限，因此是违法的价格下限是一种限制性约束，引起了过剩（也就是失业）供给、需求与政府政策*Now,theminimumwageexceedstheequilibriumwage.Theequilibriumwage(oranywagebelow$5)isillegal.Inthiscase,theactualwagewillbe$5.Itwillnotbelower,becauseanylowerwageisillegal.Itwillnotbehigher,becauseatanyhigherwage,thesurpluswouldbeevengreater.Theactualnumberofunskilledworkerswithjobsequals400.550wantjobs,butfirmsareonlywillingtohire400,leavingasurplus(i.e.unemployment)of150workers.Asurplusofanything–especiallylabor–representswastedresources.供给、需求与政府政策*最低工资法对技能高的工人并没有影响，它们影响的是青少年研究表明：最低工资每上升10%，就会使青少年就业减少1-3%。最低工资供给、需求与政府政策主动学习1价格控制决定下述政策的影响：A.价格上限为$90B. 价格下限为$90C. 价格下限为$120*Agoodexercisetobreakupthelecture,engagestudents,andassesstheirlearningsofar.主动学习1A.价格上限为$90价格降低到$90买者的需求是120个房间，而卖者只愿意供给90个房间，导致短缺*主动学习1B.价格下限为$90均衡价格高于价格下限，因此价格下限没有限制性P=$100,Q=100个房间价格下限*主动学习1C.价格下限为$120价格上升到$120。买者的需求是60个房间，而卖者的供给是120个房间，导致过剩*供给、需求与政府政策*对价格控制的评价 第一章讨论的经济学十大原理之一是：市场通常是组织经济活动的一种好方法 价格是指引社会资源配置的信号。当政府进行价格控制时，这种配置通常会发生变化 价格控制想帮助穷人，但往往却伤害了那些它本想帮助的人供给、需求与政府政策*RE:thelastbullet“pricecontrolsoftenhurtthepoormorethanhelpthem.”Wehaveseenthattheminimumwagecancausejoblosses,andrentcontrolcanreducethequantityandqualityofaffordablehousing.Bothpoliciesmakethepoorworseoff.Itmightbeworthremindingstudentsthatouranalysishasbeeninthecontextofaworldwithoutmarketfailures.Subsequentchapters(exceptinthemacrosplit)willintroducesituationsinwhichgovernmentinterventioncanimproveontheprivatemarketoutcome.However,eveninsuchcases,theappropriatepolicyisusuallysomethingotherthanadirectpricecontrol.供给、需求与政府政策*税收 政府对许多物品与劳务征税是为了给国防，公立学校等这类公共项目筹资 政府能想买者或卖者征税 税收可以是物品价格的一个比例或者每售出一单位物品需支付一定数量的货币 简化起见，我们仅分析后者供给、需求与政府政策*Theslidesinthissectionhavebeenrevisedfromthepreviousedition.TheynowbetterexplainwhyataxonbuyersshiftsDdownbytheamountofthetax,andwhyataxonsellersshiftsSupbytheamountofthetax.供给、需求与政府政策*例3:皮萨市场没有税收时的均衡供给、需求与政府政策供给、需求与政府政策*向买者征税现在买者支付的价格比市场价格要高$1.50为使买者购买相同多的数量，价格需下降$1.50例：要使买者仍愿意购买500个，市场价格需从$10.00下降到$8.50向买者征收$1.50的税收对买者征税使需求曲线向下移动，其幅度为税收量供给、需求与政府政策*NOTE:Onthisandsubsequentslides,“PB”denotesthepricebuyerspayand“PS”denotesthepricesellersreceive.(TheChapter8PowerPointusesthesamenotationforthewelfareanalysisoftaxes.)Thegovernmentmakesbuyerspaya$1.50oneachpizzatheypurchase.Thenewdemandcurve(inred,labeledD2)reflectsbuyers’demandasafunctionoftheafter-taxprice.Theoriginaldemandcurve(D1)stillreflectsbuyers’demandasafunctionofthetotalprice–inclusiveofthetax.Thus,buyers’demandhasn’treallychanged:ateachquantity,theheightoftheoriginal(blue)Dcurveisstillthemaximumthatbuyerswillpayforthatquantity,whiletheheightofthenew(red)Dcurveisthemaximumthatbuyerswillpaysellersforthatquantity,giventhatbuyersalsomustpaythetax.AtanyQ,theverticaldistancebetweentheblueandredDcurvesequalsthetax.(Ifthiswereapercentagetaxratherthanaper-unittax,thenewDcurvewouldnotbeparalleltotheoldone,itwouldbeflatter:ataxofagivenpercentagewouldbealargerdollaramountathighpricesthanatlowprices,sothedownwardshiftwouldbegreaterinabsolutetermswhenPishighthanwhenitislow.Thisisthetypeofcomplexityweavoidbyworkingwithper-unittaxes.)供给、需求与政府政策*向买者征税向买者征收$1.50的税收新均衡：Q=450卖者得到的价格：PS=$9.50买者支付的价格：PB=$11.00两者之差=$1.50=税收供给、需求与政府政策供给、需求与政府政策*税收归宿：税收负担在市场参与者之间进行分配的方式在我们的例子中，买者支付$1.00的税收卖者支付$0.50的税收.供给、需求与政府政策*“Marketparticipants”simplymeansbuyersandsellers.供给、需求与政府政策*向卖者征税向卖者征税$1.50税收增加了卖者的成本$1.50卖者只有在市场价格上升到$11.50时才愿意出售500个匹萨，因为只有如此才能弥补成本的增加因此，对卖者征税使供给曲线向上移动，移动幅度为税收量供给、需求与政府政策*Thegovernmentmakessellerspaya$1.50oneachpizzatheysell.Thenew,redsupplycurvereflectssellers’supplyasafunctionoftheafter-taxprice.供给、需求与政府政策*向卖者征税向卖者征税$1.50新的均衡：Q=450买者支付PB=$11.00卖者得到PS=$9.50两者之差=$1.50=税收供给、需求与政府政策供给、需求与政府政策*两种情况下结果是相同的!在这两种情况下：税收都在买者支付的价格和卖者得到的价格之间打入了一个契子450PB=PS=税收无论对买者还是卖者征税，最后的市场价格，均衡数量以及税收归宿都是相同的！供给、需求与政府政策*Whetherthegovernmentmakesbuyersorsellerspaythetax,alloftheeffectsarethesame:-thepricebuyerspayrises(inthiscaseto$11)-thepricesellersreceivefalls(to$9.50)-theequilibriumquantityfalls(to450)-theincidenceofthetaxisthesame(here,buyerspay$1ofthetax,whilesellerspay$.50ofthetaxoneachunit)Thisshouldmakesenseifstudentsthinkitthrough:Ataxonbuyersmeansbuyerswillhavetopaymore,whichcausestheirdemandtofall.Thefallindemandhurtssellers,forcingthemtoreducetheirprice.Similarly,ataxonsellersislikeacostincrease,andsellerspassalongaportionofthatincreasetobuyersintheformofhigherprices.Theequivalenceoftaxesonbuyersandtaxesonsellersmeansthatwecanignorewhetherthetaxisimposedonbuyersorsellers.Allthatmattersisthesizeofthetax.So,infutureproblems,wecanthinkofthetaxasawedgebetweenthepricebuyerspayandthepricesellersreceive.Onasupply-demanddiagram,thiswedgeisaverticallinesegment(showningreenonthisgraph).YoucanthinkoftakingatoothpickthesizeofthetaxandwedgingitbetweentheSandDcurves.Thequantityatwhichthetoothpickfitsjustsnugglyisthenewequilibriumquantity.Studentswillhaveachancetopracticethisinamomentwithanexercise.Onelastremark:Someoneoncesaid“ifyouwantlessofsomething,taxit.”Ataxonanygoodorservicecausesafallinitsquantity.Thisisbecausepeoplerespondtoincentives:thetaxgivesbuyersanincentivetobuylessandgivessellersanincentivetoproduceless.主动学习2税收的影响假定政府对买者所入住的每个房间都征税$30找出新的Q,PB,PS,以及税收归宿Thesearethesamesupplyanddemandcurvesusedinthepreviousexercise.主动学习2参考答案Q=80PB=$110PS=$80税收归宿买者：$10卖者：$20First,theequilibriumquantityisthequantitywherePB–PS=$30.Thisquantityis80.Next,tofindPB,startatQ=80andgouptothedemandcurvetoseethatPB=$110.TofindPS,startatQ=80andgouptothesupplycurvetoseethatPS=$80.Tofindincidence,justcomparePBandPStotheno-taxequilibriumprice,$100.供给、需求与政府政策*弹性与税收归宿 案例 全员育人导师制案例信息技术应用案例心得信息技术教学案例综合实践活动案例我余额宝案例 1:供给相对于需求更富有弹性卖者相对于买者更容易离开市场，因此买者承担了大部分税负供给、需求与政府政策*Wehavejustseenthattaxincidenceisnotaffectedbywhetherthegovernmentmakesbuyersorsellerspaythetax.Sowhat,then,doesdeterminetaxincidence?Turnsoutit’selasticity–specifically,thepriceelasticitiesofsupplyanddemand.Therearetwocases:1)supplyismoreprice-elasticthandemand(thisslide),and2)demandismoreprice-elasticthansupply(nextslide).Whensupplyismoreprice-elasticthandemand,sellersarerelativelymoreresponsivetochangesinprice,andthesupplycurveislesssteepthanthedemandcurve.Buyershaverelativelyfeweralternatives,sotheyhaveto“eat”mostofthepriceincreasecausedbytheimpositionofthetax.Asthetextbookputsit,sellerscanmoreeasilyleavethemarketinresponsetothetaxthancanbuyers.Thus,buyersarestuckbearingmostoftheburdenofthetax.供给、需求与政府政策*弹性与税收归宿案例2：需求相对于供给更富有弹性买者相对于卖者更容易离开市场，因此卖者承担了大部分的税负供给、需求与政府政策*Thesizeofthetaxisthesameinthisdiagramasintheoneontheprecedingslide.Whendemandismoreprice-elasticthansupply,buyersarerelativelymoreprice-sensitive,andthedemandcurveislesssteepthanthesupplycurve.Buyershaverelativelymorealternatives,sotheycanavoidmostofthetax.Sellersarelessflexible,sotheyhaveto“eat”agreatershareofthepriceincreasecausedbythetax.Fromthetextbook:Buyerscanmoreeasilyleavethemarketthansellersinresponsetothetax.Thus,sellersendupwithmostoftheburdenofthetax.供给、需求与政府政策*案例研究：谁支付奢侈品税 在1990年，国会通过了一项针对游艇，私人飞机，皮衣，珠宝和豪华轿车这类物品的新的奢侈品税 税收的目的；增加富人的税收 但真正支付税收的人士谁？供给、需求与政府政策*Thiscasestudyshowsstudentsaninterestingreal-worldexampleofthematerialtheyjustlearned.Ifyou’repressedfortime,itisprobablysafetoskipitandletstudentsreaditontheirown.Itdoesnotintroduceanynewconcepts,andmoststudentsdonotfinditdifficulttoread.供给、需求与政府政策*案例研究：谁支付奢侈品税游艇市场需求是富有弹性的在短期内，供给缺乏弹性因此，游艇工厂承担了大部分的税收供给、需求与政府政策*Demandforyachts(andotherluxuryitems)isprice-elastic:ifthepriceofyachtsrises,richconsumerscaneasilyavoidthetaxbyspendingtheirmillionsonsomeotherluxuryitem.Supplyofyachtsislesselastic,especiallyintheshortrun.Itisdifficultforthecompaniesthatbuildyachtstore-tooltheirfactoriesandreeducatetheirworkerstoproducesomeotherproduct.Hence,companiesthatbuildyachtspaymostofthetax,andtherichpayrelativelylittleofit.Thesameistruefortaxesonotherluxuryitems.供给、需求与政府政策*结论：政府政策与资源的配置 本章的两种政策都会影响社会资源的配置： 例1：对皮萨的征税降低了均衡数量。当皮萨的产量降低时，资源（工人，烤箱，奶酪）将会转移到其它行业 例2：一个限制性的最低工资会引起工人的超额供给，这是对资源的浪费 因此，决策者在应用这些政策时需要非常小心供给、需求与政府政策*Recalloneofthe10principlesfromChapter1:Marketsareusuallyagoodwaytoorganizeeconomicactivity.Thismeansthat,inabsenceofmarketfailures(whichwewilllearnmoreaboutinlaterchapters),theallocationofresourcesresultingfromthefreemarketequilibriumisoptimal.Hence,governmentpolicieswhichalterthisallocationtendtomaketheeconomyworseoff.Whenwestudymarketfailureslater,wewillseethatgovernmentpoliciescan–inprinciple–improveonthemarket’sallocationofresources,andmakesocietybetteroff.First,though,weneedtolearnhowtomeasuretheimpactofgovernmentpoliciesliketaxesonsociety’swell-being,aswellasdefinewhat,exactly,wemeanby“well-being.”Thisfieldofstudy,called“welfareeconomics,”isthetopicofthefollowingthreechapters.内容提要价格上限是某种物品或劳务的法定最高价格。租金控制是一个例子。如果价格上限低于均衡价格，则需求量大于供给量，会引起短缺价格下限是某种物品或劳务的法定最低价格。最低工资是一个例子。如果价格下限高于均衡价格，则供给量大于需求量，会引起劳动力超额供给，也就是失业*内容提要对一种物品征税是在买者支付的价格和卖者得到的价格之间打入的一个契子，并使均衡数量降低，无论是向买者征税还是向卖者征税税收归宿是税负在买者与卖者之间额分担，并不取决于是向买者征税，还是向卖者征税税收归宿取决于供给与需求的价格弹性*Thischapterbuildsontheprevioustwo(supply&demandandelasticity).StudentswholearnedthosechapterswellusuallydonothavemuchdifficultywiththematerialinChapter6.Thischaptercanusuallybecoveredinabout90minutesofclasstime.Ihavecombinedtheanalysisofpriceceilingswiththerentcontrolexample,andI’vecombinedtheanalysisofpricefloorswiththeminimumwageexample.(Incontrast,thetextbookpresentsagenericanalysisofpriceceilings,thentherentcontrolexample,thenagenericanalysisofpricefloors,thentheminimumwage).Moststudentslearnnewconceptsbetterinthecontextofaspecificexampleratherthanagenericanalysis,andcombiningtheminthiswaysavesclasstime.Here’sanideayoumightconsider:Attheendoftheclasssessionjustpriortotheoneinwhichyoubegintocoverthischapter,askstudentstotakeoutapieceofblankpaper,andwritedownwhethertheythinktheminimumwageshouldbeincreased,andtheirreason(s).Tellthemnottowritetheirnames(youwantthemtobecandid),andhavethemleavetheirpiecesofpaperinapileastheyexittheclassroom.Later,dividethepapersintotwogroupsbasedonwhethertheysupportoropposeincreasingtheminimumwage.InthisPowerPointfile,immediatelyafterthisslide,insertnewtwoslides,titlingthem“Yourreasonsforraisingtheminimumwage”and“Yourreasonsfornotraisingtheminimumwage.”Summarizeoneachslidethemostcommonreasonsstudentsgave.Begintheclasssessionbyshowingthemtheresultsofthisimpromptusurvey(howmanystudentsrespondedeachway,andthemostcommonreasons).Tellthosestudentsthatsupportaminimumwageincreasethattheirthinkingrepresentsthatofmanyeducatednon-economists.Buttellthemthateconomicsoffersanotherperspective,andthisissomethingtheywilllearninthischapter.Ifyoudothis,thenIrecommendrearrangingtheslidesabitsothatthepricefloor/minimumwageslidescomeBEFOREthepriceceiling/rentcontrolslides.Whenwetalkabouthowapolicy“affectsthemarketoutcome,”wemeanthepolicy’simpactonthepriceandquantityofthegoodandthereforeonthemarket’sallocationofresources.Theconcludingslideelaboratesonthisabit.*Thisslideoutlinesthechapter.*Westartbyanalyzingtheeffectsofapriceceiling.Themostcommonexampleisrentcontrol,sowedotheanalysisinthecontextofthisexample.Webeginbyshowingthemarketforapartmentsinequilibrium(beforethegovernmentimposesanypricecontrols).*Whensomestudentsseethisforthefirsttime,theywonderwhythepriceceilingdoesnotresultinasurplus.Whenthepriceceilingisabovetheequilibriumprice,theequilibriumpriceisstillperfectlylegal.Justbecauselandlordsareallowedtocharge$1000rentdoesn’tmeantheywill–iftheydo,theywon’tbeabletorentalloftheirapartments–asurpluswillresult,causingdownwardpressureontheprice(rent).There’snolawthatpreventstheprice(rent)fromfalling,soitdoesfalluntilthesurplusisgoneandequilibriumisreached(atP=$800andQ=300).*Inthiscase,thepriceceilingisbinding.Inthenewequilibriumwiththepriceceiling,theactualprice(rent)ofanapartmentwillbe$500.Itwon’tbemorethanthat,becauseanyhigherpriceisillegal.Itwon’tbelessthan$500,becausetheshortagewouldbeevenlargerifthepricewerelower.Theactualquantityofapartmentsrentedequals250,andthereisashortageequalto150(thedifferencebetweenthequantitydemanded,400,andthequantitysupplied,250).*Inthisslide,theequilibriumprice($800)andpriceceiling($500)arethesameasontheprecedingslides,butsupplyanddemandaremoreprice-elasticthanbefore,andtheshortagethatresultsfromabindingpriceceilingislarger.*Thelasttwobulletsdiscuss“efficiency”inthecontextofrationinggoodstothosebuyerswhovaluethemmosthighly.Thisconceptwillbeexploredfurtherinthefollowingchapter.*Nowweswitchgearsandlookattheeffectsofapricefloor.Weillustratethisconceptusingthecommontextbookexample–theminimumwage.Thismaybethefirsttimestudentshaveseenasupply-demanddiagramofthelabormarket.Itmightbeusefultonotethatthe“price”oflaborissimplythewage,whichwemeasureontheverticalaxisofoursupply-demanddiagram.Alongthehorizontalaxis,wemeasurethequantityoflabor(numberofworkers).Thedemandforunskilledlaborcomesfromfirms.Thesupplycomesfromworkers.Wefocusonunskilledlaborbecausetheminimumwageisnotrelevantforhigherskilled,higherwageworkers.*Somestudentsmaywonderwhythe$3pricefloordoesnotcauseashortage.Afterall,atawageof$3,thequantityofunskilledworkersthatfirmswishtohireexceedsthequantityofunskilledworkersthatarelookingforjobs.Buttheminimumwagelawdoesnotstopthewagefromrisingabove$3.So,inresponsetothisshortage,thewagewillriseuntiltheshortagedisappears–whichoccursattheequilibriumwageof$4.Theequilibriumwageisperfectlylegalwhenthepricefloor(i.e.minimumwage)isbelowit.*Now,theminimumwageexceedstheequilibriumwage.Theequilibriumwage(oranywagebelow$5)isillegal.Inthiscase,theactualwagewillbe$5.Itwillnotbelower,becauseanylowerwageisillegal.Itwillnotbehigher,becauseatanyhigherwage,thesurpluswouldbeevengreater.Theactualnumberofunskilledworkerswithjobsequals400.550wantjobs,butfirmsareonlywillingtohire400,leavingasurplus(i.e.unemployment)of150workers.Asurplusofanything–especiallylabor–representswastedresources.Agoodexercisetobreakupthelecture,engagestudents,andassesstheirlearningsofar.*RE:thelastbullet“pricecontrolsoftenhurtthepoormorethanhelpthem.”Wehaveseenthattheminimumwagecancausejoblosses,andrentcontrolcanreducethequantityandqualityofaffordablehousing.Bothpoliciesmakethepoorworseoff.Itmightbeworthremindingstudentsthatouranalysishasbeeninthecontextofaworldwithoutmarketfailures.Subsequentchapters(exceptinthemacrosplit)willintroducesituationsinwhichgovernmentinterventioncanimproveontheprivatemarketoutcome.However,eveninsuchcases,theappropriatepolicyisusuallysomethingotherthanadirectpricecontrol.*Theslidesinthissectionhavebeen