题源经济学人

题源经济学人Shake’emup,MrCarney卡尼，教教他们HowtheBankofEngland’snewgovernor(andthechancellor)shouldstimulatetheBritisheconomy英国央行新行长(还有财政大臣)应该怎样刺激英国经济?Feb2nd2013|FromtheprinteditionONFEBRUARY7thMarkCarneywillappearbeforetheTreasurySelectCommitteeforhisfirstformalgrillingfromBritishlawmakerssincebeingnamedthenextgovernoroftheBankofEngland.Thiswillbeanimportantmoment.MrCarney,hiredawayfromtheBankofCanada,hasrecentlygivenhintsthathewantstoshakeupBritishmonetarypolicy.Hehastalkedabouttheneedtostimulateaninerteconomyuntilitreaches“escapevelocity”;hehassaidthatacentralbankmightneedto“tieitshands”byannouncingthresholdstobereachedbeforeitreducesstimulus;andhehassuggestedthatthelevelofnominalGDP—thecashvalueofoutputwithoutadjustingforinflation—mightbeabettertargetthaninflationalone.Thiswillingnesstothinkafreshisadmirable.ButMrCarneymustnowconnectthedotsbetweenhisideas.英国央行行长卡尼(MarkCarney)将于2月7日公开露面，之后会接受财政部特别委员会英国立法委员的正式质询，这是他被任命为英国央行行长以来的首次质询，并且十分重要。卡尼是英国从加拿大央行聘请过来的，最近他暗示希望重新调整英国货币政策。他谈到疲软的经济需要刺激一下，直到它达到“逃脱速度”，中央银行需要“收一收手”，在减弱刺激之前宣布经济需要达到的水平。他还间接表示名义GDP(不进行通胀调整的现金产出价值)比起通胀是更好的目标。愿意重新思考经济解决方案令人钦佩，但是卡尼需要把自己的思想联系在一起AtthemomenttheBankofEngland’smission,setbythechancelloroftheexchequer,istofocusonaninflationtargetof2%.Thatmakessenseinnormalcircumstances.Butwithshort-terminterestratesatalmostzero,theeconomygrowingatbarely2%innominalterms(andnotatallifyoufactorininflation)andmanyyearsofausterityahead,itisworthtemporarilyreinterpretingthatpolicyandfocusingonnominalGDP.Oursuggestionisthatthebank,backedbythechancellor,GeorgeOsborne,shouldmakeclearthatitwillnottightenpolicyuntilnominalGDP,currently£1.5trillion,getstoalevelthatisatleast10%higherthantoday.目前财政部长给英格兰银行设定的目标是将通胀率控制在2%。这在经济状况正常的情况下是可行的，但是由于短期利率几乎为零，经济增长按名义价值计算只有2%(如果考虑通胀则没有增长)。央行将在未来一些年内实施财政紧缩，暂时重新解释货币政策和着重于名义GDP是很有必要的。我们的建议是：英格兰央行应该在奥斯本财相的支持下要清楚这一点，在名义GDP(目前为1.5万亿英镑)基础上至少10%之前，这项措施不会收紧政策。Whenshort-terminterestratesareaslowastheyarenow,centralbankerscanloosenmonetaryconditionsintwoways.Theycanuseunconventionaltools,suchas“quantitativeeasing”(printingmoneytobuybonds),topushdowninterestratesfurtheralongtheyieldcurve.Andtheycanguidepeople’sexpectationsofthefuturepathofinterestratesorinflation.Ifacentralbankcancrediblypromisetokeepmonetaryconditionslooseevenastheeconomyrecoversandinflationaccelerates,itwill,ineffect,reducethereallevelofinterestratestoday,andsoboosttheeconomy.现在短期利率维持低位，央行行长可以通过两种方式宽松货币环境。他们可以使用非常规措施把利率按照收益曲线进一步推低，如“量化宽松”(即印钞票买债券)。另外他们还可以就对未来利率或通胀的走向对人们的期望加以引导。如果央行在经济复苏和通胀加速的状况下还能确保货币环境良好，那么这项措施能有效地降低现在的真实利率水平，也能繁荣经济。TheBankofEnglandhasbeenwillingtouseunconventionaltools.Itwasanearlypioneerofquantitativeeasing;itsmorerecent“fundingforlending”schemeforbanksisacleverwaytobringdownbanks’fundingcosts(andshouldbeusedtohitthenominalGDPtarget).ButBritain’scentralbankhasbeenlesssuccessfulatmappingitsfuturepolicypath.TheBankhasinterpretedits2%inflationtargetinaflexibleway,keepingmonetaryconditionslooseevenasinflationhasstayedhigher.Butithasnotsaidhowlongsuchflexibilitywilllast.Eachtimeitsinterest-rate-settingcommitteemeets,thereisthepossibilityitwillchangeitsmind.英国央行已经愿意使用非常规措施。之前它就是量化宽松政策的'最早实施者，新近的“融资换贷款计划(fundingforlending)”是降低银行集资成本的一剂良方(也应该应用到实现名义GDP上)。但是英国央行没有很好地规划自己未来的政策路线。央行对目标通胀2%的解释比较灵活，保持货币环境即使在通胀维持高位情况下依旧宽松。但它没有说这灵活性要持续多久。央行每次开利率会议都有可能改变主意。ThatiswherethenominalGDPtargetcomesin.BypromisingtokeepmonetaryconditionslooseuntilnominalGDPhasrisenby10%,theBankwouldprovidecertaintythatinterestrateswillstaylowevenastheeconomyrecovers.Thatwillencourageinvestmentandspending.Atthesametimeanexplicittargetof10%wouldsetalimittothelooseness,preventingpeople’sexpectationsforinflationbecomingpermanentlyunhinged.ItisanapproachsimilarinspirittotheFederalReserve’srecentcommitmentnottoraiseinterestratesuntilAmerica’sunemploymentratefallsbelow6.5%.这就是为什么会使用名义GDP。通过允诺在名义GDP升至10%之前保持货币环境宽松，央行保证利率维持在低位，即使经济恢复。这样就会鼓励投资和消费。同时，10%的明确目标为宽松设置上限，防止人们对通胀的期望长久混乱。在本质精神上，这项措施类似于美联储(theFederalReserve)近期承诺提升利率直到美国失业率降至6.5%以下。Thisisnotaperfectanswer.CriticspointoutthatnominalGDPishardtomeasure—andthatnooneknowsexactlyhowbigtheshortfallinnominalGDPis,particularlysinceBritain’sproductivityhasplungedsincethefinancialcrisis.Againstthat,a10%increaseisafairlyconservativeandcleartarget.AdoptingitwouldbebetterfortheBank’scredibilitythanrepeatedlymissingtheinflationtarget.但这项措施不能完全解决问题。评论指出名义GDP难以衡量，没人准确知道名义GDP差额有多大，尤其是财政危机导致英国生产效率跳水之后。在此背景下，10%的增长相当保守，但目标明确。采取这项增长比不断错失通胀目标要有利于央行信誉。Anotherworryisthatallthegrowthwouldcomethroughinflation.Sterlingwouldfall,soimportswouldbecomepricier.Assetpricesmightbubbleup,thoughMrCarneycoulduseothertoolstocoolthem,suchaslimitingmortgagelending.Thereisinfactlittleriskofanunwantedboom.AllthiswilltakeplaceaspublicspendingissqueezedandBritain’smaintradingpartnersintheeurozonearelikelytobestruggling.再一个担忧是其它增长都在通胀中发生：英镑会贬值，因而进口更昂贵，资产价格或许会产生泡沫，尽管卡尼可以使用限制抵押贷款等其它措施为其降温。事实上发生预期外经济繁荣的风险几乎不存在。当公共开支受挤压，英国在欧元区的主要贸易伙伴可能艰难度日时，这一切都会发生。ThelastproblemisMrOsborne.Atemporarynominal-GDPtargetneedshisexplicitsupp