乔治索罗斯关于金融市场和泡沫演讲全文

2009年10月，乔治·索罗斯在位于匈牙利布达佩斯的中欧大学发表了共分五个部分的系列演讲。本文是他关于金融市场和泡沫的演讲的全文。FinancialMarketsPublished:October27200922:26|Lastupdated:October27200922:26FinancialmarketsprovideanexcellentlaboratoryfordemonstratingandtestingtheideasthatIputforwardinanabstractformyesterday.Thecourseofeventsiseasiertoobservethaninmostotherplaces.Manyofthefactstakeaquantitativeform,andthedataarewellrecordedandwellpreserved.Theopportunityfortestingoccursbecausemyinterpretationoffinancialmarketsdirectlycontradictstheefficientmarkethypothesis,whichhasbeentheprevailingtheoryaboutfinancialmarkets.Thattheoryclaimsthatmarketstendtowardsequilibrium;deviationsoccurinarandomfashionandcanbeattributedtoextraneousshocks.Ifthattheoryisvalid,mineisfalse—andviceversa.Iamnotinagoodpositiontocriticizetheprevailingparadigmdirectly.Iwentintothefinancialmarketsinordertomakemoney,andtodothatIdidnotneedtoknoweithermodernportfoliotheoryorthetheoryofrationalexpectations.Idevelopedmyowninterpretationoffinancialmarketsandputitforwardasaclearalternativetotheprevailingview.WhenIpublishedTheAlchemyofFinancein1987Ifranklyadmittedmyignoranceofthegenerallyacceptedtheories.Nowonderthattheeconomicsprofessionreciprocatedbyignoringmyinterpretation.TheGovernoroftheBankofEngland,MervynKing,didmethehonorofexplicitlydismissingmytheory,butmostothereconomistssimplyignoredit.Allthishaschangedinthewakeoftherecentfinancialcrisis.Eventshaveconclusivelydemonstratedtheinadequacyoftheefficientmarkethypothesis.Itneitherpredictednorexplainedwhathappened.Atthesametime,mywritingsprovidedaconceptualframeworkintermsofwhicheventscouldbebetterunderstood.Theybegantobetakenseriously,bothbyothers–likeMervynKing–andbymyself.Ibegantothinkthatmyinterpretationdoesprovideanewandbetterparadigm,andIputitforwardassuchinabookIpublishedearlyin2008,wellbeforethebankruptcyofLehmanBrothers.Andyetthetheoryofreflexivityisstillnotacceptedinacademiccircles.Thefailureoftheefficientmarkethypothesisisgenerallyadmitted,butinsofarasanewparadigmisemerging,itisbasedonbehavioraleconomics.Behavioraleconomicsiscompatiblewithreflexivitybut,asIwilltrytoshow,itexploresonlyonehalfofthephenomenon.***Letmestatethetwocardinalprinciplesofmyconceptualframeworkasitappliestothefinancialmarkets.First,marketpricesalwaysdistorttheunderlyingfundamentals.Thedegreeofdistortionmayrangefromthenegligibletothesignificant.Thisisindirectcontradictiontotheefficientmarkethypothesis,whichmaintainsthatmarketpricesaccuratelyreflectalltheavailableinformation.Second,insteadofplayingapurelypassiveroleinreflectinganunderlyingreality,financialmarketsalsohaveanactiverole:theycanaffecttheso-calledfundamentalstheyaresupposedtoreflect.Thatisthepointthatbehavioraleconomicsismissing.Itfocusesonlyononehalfofareflexiveprocess:themispricingoffinancialassets;itdoesnotconcernitselfwiththeimpactofthemispricingontheso-calledfundamentals.Therearevariousfeedbackmechanismsatworkwhichmayvalidatethemispricingoffinancialassets,atleastforawhile.Thismaygivetheimpressionthatmarketsareoftenright,butthemechanismatworkisverydifferentfromtheoneproposedbytheprevailingparadigm.Iclaimthatfinancialmarketshavewaysofalteringthefundamentalsandthatmaybringaboutaclosercorrespondencebetweenmarketpricesandtheunderlyingfundamentals.Contrastthatwiththeefficientmarkethypothesis,whichclaimsthatmarketsalwaysaccuratelyreflectrealityandautomaticallytendtowardsequilibrium.Therearevariouspathwaysbywhichthemispricingoffinancialassetscanaffecttheso-calledfundamentals.Themostwidelytravelledarethosewhichinvolvetheuseofleverage—bothdebtandequityleveraging.Thesepathwaysdeservealotmoreresearch.Mytwopropositionsfocusattentiononthereflexivefeedbackloopsthatcharacterizefinancialmarkets.Therearetwokindsoffeedback:negativeandpositive.Negativefeedbackisself-correcting;positivefeedbackisself-reinforcing.Thus,negativefeedbacksetsupatendencytowardequilibrium,whilepositivefeedbackproducesdynamicdisequilibrium.Positivefeedbackloopsaremoreinterestingbecausetheycancausebigmoves,bothinmarketpricesandintheunderlyingfundamentals.Apositivefeedbackprocessthatrunsitsfullcourseisinitiallyselfreinforcing,buteventuallyitisliabletoreachaclimaxorreversalpoint,afterwhichitbecomesselfreinforcingintheoppositedirection.Butpositivefeedbackprocessesdonotnecessarilyruntheirfullcourse;theymaybeabortedatanytimebynegativefeedback.***Ihavedevelopedatheoryaboutboom-bustprocesses,orbubbles,alongtheselines.Everybubblehastwocomponents:anunderlyingtrendthatprevailsinrealityandamisconceptionrelatingtothattrend.Aboom-bustprocessissetinmotionwhenatrendandamisconceptionpositivelyreinforceeachother.Theprocessisliabletobetestedbynegativefeedbackalongtheway.Ifthetrendisstrongenoughtosurvivethetest,boththetrendandthemisconceptionwillbefurtherreinforced.Eventually,marketexpectationsbecomesofarremovedfromrealitythatpeopleareforcedtorecognizethatamisconceptionisinvolved.Atwilightperiodensuesduringwhichdoubtsgrow,andmorepeopleloosefaith,buttheprevailingtrendissustainedbyinertia.AsChuckPrince,formerheadofCitigroupsaid:wemustcontinuedancinguntilthemusicstops.Event