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Tiêu đề Cyclical Effects Of Bank Capital Requirements With Imperfect Credit Markets
Tác giả Pierre-Richard Agộnor, Luiz A. Pereira Da Silva
Trường học University of Manchester
Chuyên ngành Social Sciences
Thể loại Article
Năm xuất bản 2012
Thành phố Manchester
Định dạng
Số trang 14
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Nội dung

Most existing studies of thecyclicality of capital regulatory regimes, both theoretical and empirical, are based on indus-trialized countries.3 However, the pervasiveness of financial mar

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journal homepage:www.elsevier.com/locate/jfstabil

Pierre-Richard Agénora,b,∗, Luiz A Pereira da Silvac

a r t i c l e i n f o

Available online 11 August 2010

PACS:

E44

H52

G28

Keywords:

a b s t r a c t

Thispaperanalyzesthecyclicaleffectsofbankcapitalrequirementsinasimplemodelwithcreditmarket imperfections.Lendingratesaresetasapremiumoverthecostofborrowingfromthecentralbank,with thepremiumitselfdependingoncollateral.BaselI-andBaselII-typeregulatoryregimesaredefinedand

acapitalchannelisintroducedthroughasignalingeffectofcapitalbuffers.Themacroeconomiceffectsof

anegativesupplyshockareanalyzed,underbothbindingandnonbindingcapitalrequirements.Factors affectingtheprocyclicalityofeachregime(definedintermsofthebehavioroftheriskpremium)arealso identified

© 2010 Published by Elsevier B.V

1 Introduction

The global financial crisis triggered by the collapse of the

subprime mortgage market in the United States has led to a

reassessment of the policies and rules that have allowed the

buildupoffinancialfragilities.Theregulatoryframework,andthe

distortionsinbankbehaviorandthefinancialintermediation

pro-cessthatitmayhaveledto,havecomeunderrenewedscrutiny

Indeed,itisnowwellrecognizedthattheBaselIregulatorycapital

regimethatU.S.banksweresubjecttogavethemstrongincentives

toreducerequiredcapitalbyshiftingloansofftheirbalancesheets.1

Banksturnedtoan“originateanddistribute”model,inwhich

luiz.apereira@bcb.gov.br (L.A Pereira da Silva).

dardizedloans,mostlyhigh-riskmortgages—involvingnomoney down,interestonlyorlessastheinitialpayment,withno documen-tationonborrowers’capacitytopay,andinitial“teaser”interest rates that would adjustupwardeven if marketrates remained constant—couldbebundledandsoldassecurities,therebyleaving theoriginatingbankfreetouseitscapitalelsewhere.Asthehousing marketdeteriorated,anduncertaintyabouttheunderlyingvalue

ofsubprimemortgage-backedsecuritiesmounted,effortsto main-taincapitaladequacyledtomassivedeleveraging,capitalhoarding, liquidityshortages,andcontractionsincreditsupply,withadverse consequencesforthefunctioningofbothrealandfinancialmarkets (seeCalomiris,2009;Kashyapetal.,2009)

Since consultationsontheBasel IIaccordstarted, and since itseventualadoption in2004,therehasbeenabroaderdebate

ontheprocyclicalityeffectofprudentialandregulatoryrulesand practices.2WithBaselII,capitalrequirementsarebasedonasset qualityratherthanonlyonassettype,andbanksmustuse “mark-ingtomarket”topriceassets,ratherthanbookvalue.Astherules makebankcapitalrequirementsmoresensitivetochangesinthe

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overthebusinesscycle,therequiredregulatorycapitalvarieswith

thebusinesscycle.Forinstance,whenassetpricesstartdeclining,

banksmaybeforcedtoundertakecontinuouswritedowns

(accom-paniedbyincreasedprovisioning),andthisraisestheirneedfor

capital.Capitalrequirementsmaythereforeincreaseinacyclical

downturn.Ifbanksarehighlyleveraged,tomaintaintheircapital

ratioduringarecession,theymusteitherraisecapital(whichis

dif-ficultand/orcostlyinbadtimes)orcutbacktheirlending,which

inturntendstoamplifythedownturn.Thus,theintroductionof

risk-sensitivecapitalchargesmaynotonlyincreasethevolatility

ofregulatorycapital,itmayalso(bylimitingbanks’abilitytolend)

exacerbateaneconomicdownturn

Most existing studies of thecyclicality of capital regulatory

regimes, both theoretical and empirical, are based on

indus-trialized countries.3 However, the pervasiveness of financial

marketimperfectionsindevelopingcountries,coupledwiththeir

greater vulnerability to shocks, makes a focus onthese

coun-trieswarranted.Formiddle-incomecountries,inparticular,these

imperfections cover a broad spectrum: underdeveloped capital

markets,whichimplylimitedalternatives(suchascorporatebonds

andcommercialpaper)tobankcredit;limitedcompetitionamong

banks; more severe asymmetric information problems, which

makescreeningoutgoodfrombadcreditrisksdifficultandfosters

collateralizedlending;apervasiveroleofgovernmentinbanking,

both directly or indirectly;uncertain publicguarantees;

inade-quatedisclosureandtransparency,coupledwithweaksupervision

andalimitedabilitytoenforceprudentialregulations;weak

prop-ertyrightsandaninefficientlegalsystem,whichmakescontract

enforcementdifficultandalsoencouragescollateralizedlending;

andavolatileeconomicenvironment,which increasesexposure

toadverseshocksandmagnifies(allelseequal)boththe

possibil-ityofdefaultbyborrowersandtheriskofbankruptcyoffinancial

institutions.Oneimplicationisthatalargemajorityofsmalland

medium-sizefirms(operatingmostlyintheinformalsector)are

simplysqueezedoutofthecreditmarket,whereasthosewhodo

haveaccesstoit—well-establishedfirms,oftenbelongingto

mem-bersofthelocalelite—faceanelasticsupplyofloansandborrow

attermsthatdependontheirabilitytopledgecollateral.Credit

rationing—whichresultsfundamentallyfromthefactthat

inade-quatecollateralwouldhaveledtoprohibitiverates—istherefore

largely“exogenous.”Asecondimplicationistheimportanceofthe

costchannel,whichbecomesakeypartofthemonetary

transmis-sionmechanism.4Thegoalofthispaperistoanalyzethecyclical

effects of BaselI- and BaselII-type capital standards in a

sim-plemacroeconomic modelthatcapturessomeofthesefinancial

featuresandimplications.Asitturnsout,akeyvariableinthe

deter-minationofmacroeconomicequilibriumistheriskpremiumthat

bankschargetheircustomers,dependingontheeffectivecollateral

thattheycanpledge

Thepapercontinuesasfollows.Section2presentsthemodel

BaselI-andBaselII-typeregulatorycapitalregimesaredefined,the

latterbylinkingtheriskpremiumonloanstoriskweights.A“bank

Bikker and Metzemakers (2004) , Gordy and Howells (2006) , and Van Roy (2008) For

and Li (2008) , and the literature surveys by Drumond (2008) , and VanHoose (2007)

Pereira da Silva (2009) provides references to the limited literature on

capitalchannel”isaccountedforbyintroducingasignalingeffectof capitalbuffersonbankdepositrates;thisdifferssignificantlyfrom theliteratureonthistopic,whichtendstofocusonthefinancing choicesofbanksinanenvironmentwheretheModigliani–Miller theoremfails(see,forinstance,VandenHeuvel,2007).Section3 focusesonthecasewherecapitalrequirementsarenotbindingand studiestheimpactofanegativesupplyshockonmacroeconomic equilibriumandthedegreeofcyclicalityoflendingandinterest rates.5Thefinalsectionofferssomeconcludingremarks

2 The model

Themodelthatwedevelopbuildsonthestatic,open-economy frameworkwithmonopolisticbankingdevelopedbyAgénorand Montiel(2008a).Inwhatfollowswedescribethebehaviorofthe fourtypesofagentsthatpopulatetheeconomy,firms,households,

asinglecommercialbank,andthecentralbank

2.1 Firms Firmsproducea single,homogeneousgood Tofinancetheir workingcapitalneeds,which consistsolely oflaborcosts,firms mustborrowfromthebank.Totalproductioncostsfacedbythe representativefirmarethusequaltothewagebillplusthe inter-estpaymentsmadeonbankloans.Forsimplicity,wewillassume thatloanscontractedforthepurposeoffinancingworking capi-tal(whichareshort-terminnature),arefullycollateralizedbythe firm’scapitalstock,andarethereforemadeataratethatreflects onlythecostofborrowingfromthecentralbank,iR.Firmsrepay workingcapitalloans,withinterest,attheendoftheperiod,after goodshavebeenproducedandsold.Profitsaretransferredatthe endofeachperiodtothefirms’owners,households

Let W denote the nominal wage, N the quantity of labor employed,andiR theofficialratechargedbythecentralbankto thecommercialbank(ortherefinancerate,forshort);thewagebill (inclusiveofborrowingcosts)isthus(1+iR)WN.Themaximization problemfacedbytherepresentativefirmcanbewrittenas

whereYdenotesoutputandPthepriceofthegood

Theproductionfunctiontakestheform

whereA>0isasupplyorproductivityshock,K0isthe beginning-of-periodstockofphysicalcapital(whichisthereforepredetermined), and˛∈(0,1)

Solvingproblem(1)subjectto(2),takingiR,PandWasgiven, yields

˛APN˛−1K01−˛−(1+iR)W=0

Thisconditionyieldsthedemandforlaboras

Nd=



˛AK01−˛

(1+iR)(W/P)

1/(1 −˛)

whichcanbesubstitutedin(2)togive

(1+iR)(W/P)

˛/(1−˛)

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areinverselyrelatedtotheeffectivecostoflabor,(1+iR)(W/P)

Giventheshortrunnatureofthemodel,thenominalwageis

assumedtoberigidat ¯W 6Thisimplies,from(3)and(4),that

Nd=Nd(P;iR,A), Ys=Ys(P;iR,A), (5)

withNd,Ys

P>0,Nd

iR,Ys

iR<0,andNd

A,Ys

A>0.7Anincreasein bor-rowingcostsorareductioninprices(whichraisestherealwage)

exertacontractionaryeffectonoutputandemployment

Realinvestmentisnegativelyrelatedtothereallendingrate:

whereiListhenominallendingrate,atheexpectedrateof

infla-tion,andh<0.8

Using(5)and(6),thetotalamountofloansdemanded(and

allo-catedbythebank)tofinancelaborcostsandcapitalaccumulation,

LF,isthus

2.2 Households

Householdssupplylaborinelastically,consumegoods,andhold

two imperfectlysubstitutable assets:currency (whichbears no

interest),innominalquantityBILL,andbankdeposits,innominal

quantityD.Becausehouseholdsownthebank,theyalsoholdequity

capital,whichisfixedat ¯E.9Householdfinancialwealth,FH,isthus

definedas:

Therelativedemandfor currencyisassumedtobeinversely

relatedtoitsopportunitycost:

BILLH

whereiDistheinterestrateonbankdepositsand<0.Using(8),

thisequationcanberewrittenas

D

wherehD(iD)=1/[1+(iD)]andhD>0.Thus,

BILLH

wherehB=(iD)/[1+(iD)]andhB<0

Realconsumptionexpenditurebyhouseholds,C,depends

neg-ativelyontherealdepositrate(whichcapturesanintertemporal

effect)andpositivelyonlaborincomeandtherealvalueofwealth

atthebeginningoftheperiod:10

C=˛0+˛1

¯

W N

P −˛2(iD−a)+˛3



FH 0

P



where aistheexpectedinflationrate,˛1∈(0,1)themarginal propensitytoconsumeoutofdisposableincome,and˛0,˛2,˛3>0 Thepositiveeffectofcurrentlaborincomeonprivatespendingis consistentwiththeevidenceregardingthepervasivenessof liq-uidity constraintsin middle-incomecountries(see Agénor and Montiel, 2008b)and the(implicit)assumption that households cannotborrowdirectlyfrombankstosmoothconsumption 2.3 Commercialbank

Assetsofthecommercialbankconsistoftotalcreditextended

tofirms,LF,andmandatoryreservesheldatthecentralbank,RR Thebank’sliabilitiesconsistofthebookvalueofequitycapital, ¯E, householddeposits,andborrowingfromthecentralbank,LB.The balancesheetofthebankcanthereforebewrittenas:

Reservesheldatthecentralbankpaynointerestandaresetin proportiontodeposits:

where∈(0,1)

2.3.1 Interestratepricingrules The bank is risk-neutral and sets both deposit and lending rates.11

2.3.1.1 Depositrateandcapitalbuffers Fromthemonopolybank optimizationproblemdescribedinAgénorandMontiel(2008a), thedepositrateisgivenby

iD=



1+ 1

D

−1

whereDistheinterestelasticityofthesupplyofdeposits

We alsoconsidera more generalspecification, inwhich the bank’scapitalpositionaffectsitsfundingcosts,througha “signal-ing”effect.Specifically,weassumethatthebank’scapitalbuffer (asmeasuredbytheratioofactualtorequiredcapital)allowsit

toraisedepositsmorecheaply,becausehouseholdsinternalizethe factthatbankcapitalincreasesitsincentivestoscreenandmonitor itsborrowers.Depositors,therefore,arewillingtoacceptalower, butsafer,return.12

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capitalbuffer, measuredasaratio,isthus ¯E/ER.Thealternative

specificationthatweconsideristhus

iD=εD(1−)iRf



¯E

ER



whereεD=(1+1/D)−1,0<f(·)≤1,f<0, and f(1)=1.The

lastconditionimpliesthatif ¯E=ER,bankcapitalhasnoeffecton

thedepositrate,asspecifiedin(15).Thestrengthofthebank

cap-italchannel,asdefinedhere,canthereforebemeasuredbyf

However,from(12),whethertheexistenceofthischannel(which

operatesthroughthedepositrate)mattersdependsonthe

pres-enceofanintertemporalsubstitutioneffectonconsumption

Modelsconsistentwiththisidea(andwithmorerigorousmicro

foundations)aredevelopedinChen(2001),wherebanks,which

actasdelegatedmonitors,mustbewell-capitalizedtoconvince

depositorsthattheyhaveenoughatstakeinfundingriskyprojects,

andwithAllenetal.(2009),whohavearguedthatmarketforces

leadbankstokeepcapitalbuffers,evenwhencapitalisrelatively

costly,asbankcapitalcommitsthebanktomonitorand,without

depositinsurance,allowsthebanktoraisedepositsmorecheaply

Our specificationis alsoconsistentwiththeview,discussed by

CalomirisandWilson(2004),thatdepositorshavealow

prefer-enceforhigh-riskdepositsandmaydemanda“lemonspremium”

(orpenaltyinterestrate)asaresultofaperceivedincreaseinbank

debtrisk.Tolimitthisrisk(andthereforereducedepositrates),

banksmayrespondbyaccumulatingcapital.Thisviewissupported

bytheempiricalresultsofDemirgüc¸-KuntandHuizinga(2004),

whichshowanegativerelationshipbetweendepositsratesand

theratioofbankcapitaltobankassets.Moredirectsupportis

pro-videdbyFonsecaetal.(2010),inastudyofpricingbehaviorby

morethan2300banksin92countriesovertheperiod1990–2007

Theyfoundthatcapitalbuffers(definedas( ¯E−ER)/ER,ratherthan

¯E/ER)arenegativelyandsignificantlyassociatedwithdepositrate

spreads,regardlessoftheregulatoryregime.Moreover,this

asso-ciationappearstobestrongerfordevelopingcountries,compared

toindustrialcountries

Alternatively,thelinkbetweenthecapitalbufferanddeposit

ratescouldreflectthefactthatwell-capitalizedbanksfacelower

expectedbankruptcycosts(thatis,lowerexpostmonitoringcosts

in case ofdefault)and hence lowerfundingcostsexante from

households.Whatevertheinterpretation,thegeneralpointisthat

in a volatile economic environment, where therisk of adverse

shocksishigh,signalsaboutabank’ssolvencycanhavea

signifi-canteffectondepositors’behavior—particularlywhengovernment

depositguarantees(intheformofadepositinsurancesystem,for

instance)donotexistorarenotreliable.13

2.3.1.2 Lendingrateandthe riskpremium Again,fromthebank

optimizationproblemdescribedinAgénorandMontiel(2008a),

thecontractuallendingrate,iL,isgivenby

whereεL=(1+1/L)−1,withLdenoting(theabsolutevalueof)

theinterestelasticityofthedemandforinvestmentloans,andL

therisk premium, which is inversely related totherepayment

(2004) focus on the behavior of New York City banks during the 1920s and 1930s.

probability.Thus, thelendingrateissetasapremiumoverthe centralbankrefinancerate,whichrepresentsthemarginalcostof funds.Withnonbindingcapitalrequirements,weassumethatthe premiumisinverselyrelatedtotheasset-to-liabilityratioofthe borrower,givenbythe“effective”valueofcollateralpledgedby theborrower(thatis,assetsthatcanbeborrowedagainst)divided

byitsliabilities,thatis,borrowingforinvestmentpurposes,I.In turn,the“effective”valueofcollateralconsistsofafraction∈(0, 1)ofthevalueofthefirm’soutput:

L=g

Ys

whereg<0.This specificationis consistentwith theviewthat collateral,byincreasingborrowers’effortandreducingtheir incen-tivestotakeonexcessiverisk,reducesmoralhazardandraisesthe repaymentprobability—inducingthebankthereforetoreducethe premiumonitsloansforinvestmentpurposes.14Thus,anincrease

ingoodsorassetprices,orareductioninborrowing,tendstoraise thefirm’seffectiveasset-to-liabilityratioandtoreducetherisk premiumdemandedbythebank

2.3.2 Capitalrequirements Capitalrequirementsare based onthe bank’srisk-weighted assets.Supposethattheriskweighton“safe”assets(reservesand loansforworkingcapitalneeds)are0,whereastheriskweight

oninvestmentloansis >0,respectively.Risk-weightedassetsare thus PI.Thecapitalrequirementconstraintcanthereforebe writ-tenas

where ∈(0,1)isthecapitaladequacyratio(theso-calledCooke’s ratio).Ifthepenalty(monetaryorreputational)costofholding cap-italbelowtherequiredlevelisprohibitive,wecanexcludethecase where ¯E<ER;theissueisthereforewhether ¯E=ERor ¯E>ER

Weconsidertwoalternativeregimesforthedeterminationof theriskweight Underthefirstregime,whichcorrespondsto BaselI,theriskweightisexogenousat R;thebankkeepsaflat minimumpercentageofcapitalagainstloansprovidedforthe pur-poseofinvestment.Underthesecond,whichcorrespondstoBasel

II,capitalrequirementsarerisk-based;theriskweightis endoge-nousandinverselyrelatedtoloanquality,whichinturnisinversely relatedtotheriskpremiumimposedbythebank,L.Thisis simi-larinspirittolinkingtheriskweighttotheprobabilityofdefault

ofborrowers,asproposedbyHeid(2007).Thus,asallowedunder BaselII,weassumethatthebankusesanIRBapproach,oritsown defaultriskassessment,incalculatingtheappropriateriskweight andby implicationrequired regulatorycapital.Thisassumesin turnthatthestandardsembeddedinthebank’sriskmanagement systemhave beenvalidated by theregulator—the centralbank here—throughanInternal CapitalAdequacyAssessmentProcess (ICAAP).15

Formally,thetworegimescanbedefinedas16 =

R≤1 under Basel I

Montiel (2008a,b) There is therefore no “balance sheet” or “net worth” effect on

effect.

16

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inpartial equilibrium,a negativesupply shock(afallin A)

low-erseffectivecollateralandraisestheriskpremiumoninvestment

loans, L; underBasel II,therisk weight associatedwith these

loans, (L),andcapitalrequirementsalsoincreaseandbank

lend-ingfor investmentmust fallifthe capitalconstraint is binding

( ¯E=ER)

Thelinkbetween andLunderBaselIIisconsistentwith

spec-ificationsthatrelateriskweightstotheborrower’sprobabilityof

defaultoverthebusinesscycle,asforinstanceinTanaka(2002)

andHeid(2007).Theseresultscaptureoneofthegeneralconcerns

aboutBaselII:duringarecessionforinstance(say,anegative

sup-plyshock,asdiscussedhere),iflendingtofirmsisconsideredriskier

becausecollateralvaluesfall,thebankwillberequiredtoholdmore

capital—or,failingthat,toreducelending(indirectlyinthepresent

case,byincreasingtheriskpremium).Inturn,thecreditcrunchwill

exacerbatetheeconomicdownturn,makingcapitalrequirements

procyclical

However,inthepresentsettingtherearealsoanumberofother

(endogenous)factorsthatwillaffectthepremium.Thefallin

lend-ingthatmayresultfromabindingcapitalconstraintfollowingan

increaseinrisktendsnotonlytoreduceoutputbutalsothe

col-lateralrequiredbythebank;thisdampenstheinitialincreasein

thepremium.Inaddition,changesinlendingandaggregate

sup-plywillaffectprices,whichwillaffecttheequilibriumvalueofthe

premiumaswell.Withthebankcapitalchannelembeddedinthe

model,changesinthecapitalbufferwillalsoaffectthedepositrate

andconsumption,whichinturnwillaffectaggregatedemandand

prices.Theseinteractionsimplythattheneteffectofshockscanbe

fullyassessedonlythroughageneralequilibriumanalysis

2.3.3 Borrowingfromthecentralbank

Giventhatfirms’demandforcreditdeterminestheactual

sup-ply of loans, and that the required reserve ratio is set by the

monetaryauthority,thebalancesheetcondition(13)canbesolved

residuallyforborrowingfromthecentralbank,LB.Becausethereis

noreasonforthebanktoborrowifitcanfunditsloanoperations

withdeposits,andusing(14),wehaveLB=max[0,LF−(1−)D−

¯E].17

2.4 Centralbank

Thebalancesheetofthecentralbankconsists,ontheassetside,

ofloanstothecommercialbank,LB.Ontheliabilityside,itconsists

onlyofthemonetarybase,MB:

where

Monetarypolicyisoperatedbysettingtherefinancerateatthe

constantrateiR andprovidingliquidity(atthediscretionofthe

commercialbank)throughastandingfacility

Becausecentralbankliquidityisendogenous,themonetarybase

isalsoendogenous;thisimplies,using(14)and(21),thatthesupply

ofcurrencyis

2.5 Market-clearingconditions Therearefivemarketequilibriumconditionstoconsider:four financial(deposits,loans,centralbankcredit,andcash),andonefor thegoodsmarket.Marketsfordepositsandloansadjustthrough quantities,withthebanksettingpricesinbothcases.Thesupplyof centralbankcreditisperfectlyelasticattheofficialrefinancerate

iRandthemarketalsoequilibratesthroughquantityadjustment Theequilibriumconditionofthegoodsmarket,which deter-minesthegoodspriceP,isgivenby:

Thelastequilibriumconditionrelatestothemarketforcash,and (undertheassumptionthatthecounterparttobankloansisheld

byfirmsintheformofcurrency)involves(11)and(23).However, thereisnoneedtowritethisconditionexplicitly,giventhatby Walras’Lawitcanbeeliminated.18

Table1summarizesthelistofvariablesandtheirdefinitions

3 Nonbinding capital requirements

Wefirstconsiderthecasewhereexistingequitycapitalishigher thantherequiredvalue,thatis, ¯E>ER,regardlessofwhether is endogenousornot.Thisisconsistentwiththeevidencesuggesting that,innormaltimes,banksoftenholdmorecapitalthanthe reg-ulatoryminimum—possibly asa resultof marketdiscipline(see Rochet, 2008).However,although bankcapitalis nota binding constraintonthebank’sbehavior,itstillplaysanindirectrole,by affectinghowthebanksetsthedepositrate.19

3.1 Macroeconomicequilibrium ThesolutionofthemodelisdescribedinAppendixA,underthe assumptionsthata==0and ¯W=1.Asshownthere,themodel canbecondensedintotwoequilibriumconditionsintermsofthe riskpremium,L,andthepriceofthedomesticgood,P:

L=g

 Ys(P;iR,A) h[εL(1+L)iR]



Ys(P;iR,A)=˛1

Nd(P;iR,A)

P −˛2εDiRf

¯E

L(1+L)iR]

0 − L F ) + (LB,d1 − L B − L B )

1 − L F

0 , L B =

cash.

Trang 6

Table 1

Households

F H

Firms

Commercial bank

i D , i L Bank interest rates, deposits and investment loans

Central bank

Capital adequacy ratio

Fig 1.Macroeconomic equilibrium with nonbinding capital requirements.



0

P



whereasthesecondisthegoodsmarketequilibriumcondition(24),

aftersubstitutionfrom(5),(6),(12),(16),(17),and(20)

AgraphicalpresentationoftheequilibriumisshowninFig.1.In

thenortheastquadrantofthefigure,thefinancialequilibriumcurve

(25)islabeledFF.AsshowninAppendixA,FFdoesnotdependon theregulatoryregime;itslopeisgivenby

dL dP



NB,FF

I,II

= g

˙



Ys P

h



<0,

whereNBstandsfor“nonbinding”and˙>0isdefinedinAppendix

A.Intuitively,ariseinpricesstimulatesoutputandincreasesthe effectivevalueoffirms’collateralrelativetotheinitialdemandfor loans;theriskpremiummustthereforefall,attheinitiallevelof investment

Thegoodsmarketequilibriumcondition(26)yieldsthecurves labeledG1G1(whichcorrespondstotheBaselIregime)andG2G2

(correspondingtotheBaselIIregime).Theslopesofthesecurves aregivenby,respectively

dL

dP



NB,GG

I

1

YPs+˛1

P2(Nd−PNd)−˛2εDiRf ¯E

R 2h

+˛3



FH 0

P2



where 1<0if ˛2 is not toolarge(seeAppendix A)and, with (L)= Rinitially,

dL dP



NB,GG

II

=

1

2

dL dP



NB,GG

I

where 2<0and 2> 1.Thus,acomparisonof(27)and(28) impliesthatG2G2isflatterthanG1G1.Inspectionoftheseresults alsoshowsthatcurvesG1G1andG2G2haveasteeperslopethanin theabsenceofabankcapitalchannel(f=0),givenby

dL dP



GG= 1

εLiRh

YPs+˛1

P2(Nd−PNd)+˛3



FH 0

P2



, whichistheslopeofcurveGGinFig.1

Intuitively,thenegativeslopeoftheGGcurvescanbeexplained

asfollows.Ariseinpricestendstoloweraggregatedemandthrough

a negativewealth effecton consumption Atthe same time, it increasesthe nominal valueof loans and thus capital require-ments;thefallinthecapitalbufferraisesthedepositrate,which (throughintertemporalsubstitution)lowerscurrentconsumption However,theincreaseinPalsoboostsaggregatesupply,by reduc-ingthereal(effective)wage,andmaystimulateconsumption,as

aresultofhigherlabordemandanddistributedwageincome.20 Becausethe shiftin supply outweighsthewage income effect, andbecausethewealthandcapitalbuffereffectsare unambigu-ouslynegative,anincreaseinpricescreatesexcesssupply.Therisk premiummustthereforefalltostimulateinvestmentandrestore equilibriuminthegoodsmarket.ThisimpliesthattheGGcurves haveanegativeslope,asshowninthefigure

Curves G1G1 and G2G2 are steeper than curve GG (which correspondstof=0)becausethebankcapitalchanneladds addi-tionaldownwardpressureonconsumption—requiringthereforea largerfallinthepremiumtogenerateanoffsettingexpansionin investment.21

Byimplication, theintuitivereason whyG2G2 is flatterthan

G1G1 isbecauseunderBaselIIthereisanadditionaleffect—the

Trang 7

Fig 2. Negative supply shock with nonbinding capital requirements.

fallintheriskpremiumalludedtoearlierlowerstheriskweight

Thismitigatesthereforetheinitialdropinthecapitalbuffer(atthe

initiallevelofinvestment)inducedbytheriseinprices.Inturn,

thisdampenstheincreaseinthedepositrateandthedropin

con-sumption.Giventhataggregatesupplyandwageincomeincreases

inthesameproportioninbothregimes,theriskpremiummust

fallbylessunderBaselIItostimulateinvestmentandreestablish

equilibriumbetweensupplyanddemand

Understandarddynamicassumptions,localstabilityrequires

theGG curvestobesteeperthanFF.22Thepositiverelationship

betweentheriskpremiumandthelendingrateisshowninthe

northwestquadrant,whereasthenegativerelationshipbetween

thelending rate and investment is displayedin the southwest

quadrant.Thesupplyofgoods,whichisanincreasingfunctionof

thepricelevel,isshowninthesoutheastquadrant.Thedifference

betweensupplyandinvestmentinthesouthwestquadrantgives

privatespending,C.Theeconomy’sequilibriumisdeterminedat

pointsE,D,H,andJ.23

3.2 Negativesupplyshock

Considerfirstanegativeshocktooutput,thatis,adropinA.24

TheresultsareillustratedinFig.2;becausethedifferencebetween

thetworegulatoryregimesisonlyintermsoftheslopeofcurveGG,

weconsideronlytheBaselIregime,toavoidclutteringthegraph

(2008a)

unnecessarily.Differencesbetweenthetworegimesarepointed outlater.WealsofocusatfirstonthemovementleadingtopointE Thefirsteffectoftheshockisofcourseadropinoutput;as showninthesoutheastquadrant,thesupplycurveshiftsinward, withoutput(attheinitiallevelofprices)droppingfromHtoM.The dropinoutputlowersthevalueofcollateralattheinitiallevelof investment;thepremiummustthereforeincreasetoaccountfor thefactthatlendinghasnowbecomemorerisky.CurveFFtherefore shiftsupward,andLrisesfirstfromEtoB.Thefallinoutputalso leadstoexcessdemandonthegoodsmarket;atinitialprices,the riskpremiummustthereforeincreasetorestoreequilibrium(by loweringinvestment).CurveG1G1thereforeshiftsalsoupward Thereis,however,“overshooting”inthebehaviorofthe pre-mium; the initialincrease is not sufficient to eliminate excess demandthroughadropininvestmentonly—todosowouldrequire

anincreasefromEtoB,whichisnotfeasible.Accordingly,prices mustincrease,whichtend(throughanegativewealtheffect)to lowerconsumptionaswell.Becausetheincreaseinpricesalso low-ersrealwages,theinitialdropinoutputisdampened;afterfalling fromHtoM,outputrecoversgraduallyfromMtoH.The associ-atedincreaseinthevalueofcollateralallowsthepremiumtofall, fromBtothenewequilibriumpoint,E.Inthenewequilibrium,the lendingrateishigher,investmentlower,andsoisconsumption However,itisalsopossibleforthenewequilibriumtobe char-acterizedbyalowerpremiumandhigherprices;thisisillustrated

bythecurvesintersectingatpointE”’inFig.2.Thiscorrespondsto

acasewherecurveFFshiftsonlyslightly(whichoccursiftherisk premiumdoesnotadjustrapidlytochangesinthecollateral-loan ratio,thatis,gissmall)andG1G1shiftsbyalargeamount(which occursifinvestmentisnotverysensitivetothelendingrate).25 Fol-lowinganupwardjump(fromEtoB),thepremiumundergoesa prolonged“decelerator”effect,eventuallywithasmalleradverse effectoninvestment,butatthecostofhigherprices.26

Howdoesthe“capitalchannel”operateinthissetting?Because investmentfalls,capitalrequirementsalsofall.Thisimpliesthatthe bank’scapitalbufferincreases.Throughthesignalingeffect dis-cussedearlier(f<0),thedepositratefalls;this,inturn,tendsto increaseconsumptiontoday(allelseequal)throughintertemporal substitution.Putdifferently,althoughbankcapitalhasnodirect effectonloans,itdoeshaveindirecteffects,totheextentthatit affectsdepositrates,aggregatedemand,andthusprices—whichin turnaffectoutput,collateral,andtheriskpremium.This transmis-sionchannelissimilarunderbothregulatoryregimes—exceptthat withBaselIItheeffectonpricearemagnifiedandtheeffectonthe riskpremiumismitigated

Moreformally,letusdefineavariablexasbeingisprocyclical (countercyclical)withrespecttoanexogenousshockzifits move-mentinresponsetoz,asmeasuredbythefirstderivativedx/dz,is suchastoamplify(mitigate)themovementinequilibriumoutput

inresponsetothatshock,dY/dz.Inthepresentsetting,wecanfocus

ontheriskpremium,giventhatthesupplyofloansisperfectly elas-tic,andthattherealdemandforcreditforthepurposeoffinancing workingcapitalneedsis(bydefinition)procyclical.Here,wehave dL/dA+0,whichimpliesthattheriskpremiumcanbeeither pro-cyclicalwithrespecttoA—fallingduringboomsandrisingduring

as in Agénor and Montiel (2008a) , in terms of the value of the beginning-of-period

Trang 8

out-put,asperthedefinitionabove—orcountercyclical(dL/dA>0).This

ambiguityexistsregardlessoftheregulatoryregime,becauseitholds

evenintheabsenceofabankcapitalchannel(f=0or˛2=0)—given

thatinthiscaseneitherFF,norGG,dependson

Inthecasewheref>0(and˛2>0),theimpactoftheregulatory

regimeonthedegreeofprocyclicalityoftheriskpremiumcanbe

formallyassessedbycalculatingthederivativeoftheequilibrium

outcomedL/dAwithrespectto␴,thatis,d2L/dAd ,inamanner

similartoHeid(2007).Moreintuitively,thisoutcomecanbegauged

byexamininghow affectstheslopesofFFandGG.Asnotedearlier,

FFdoesnotdependon ;G2G2isflatterthanG1G1;andboth ¯E and

G2G2haveasteeperslopewithf>0thanwithf=0

By implication,withnonbindingcapital requirements, anda

bankcapital channel,bothregulatoryregimesmagnifythe

pro-cyclical effectofa negativesupply shockontheriskpremium;

allelseequal,BaselIIislessprocyclicalthanBaselI.Intuitively,

thereasonwhytheregulatorycapitalregimemagnifiesanupward

movementintheriskpremiumcomparedtothecasewherethe

regimedoesnotmatter(f=0)isbecausetheimprovementinthe

capitalbuffertends(asnotedearlier)tostimulateprivate

consump-tion;consequently,attheinitiallevelofprices,“bringingdown”

aggregatedemandtothelowerlevelofoutputrequiresalarger

dropin investment—andthereforea largerincrease in the

pre-mium.ThismovementisalsomoresignificantintheBaselIregime,

becauseinthecaseofBaselIItheinitialincreaseinthepremium

raisestheriskweight—whichinturnlimitsthedownwardeffecton

capitalrequirementsresultingfromthefallinthelevelof

invest-ment(thatis,ERfallsbylessthanthedropinIbecause rises);

asaresult,theincreaseinthecapitalbufferislesssignificant,the

depositratefallsbyless,andthestimulustoconsumptionis

miti-gated.Theriseintheriskpremiumrequiredtorestoreequilibrium

tothegoodsmarketisthusofalowermagnitude

4 Binding capital requirements

Wenowconsiderthecasewherethecapitalrequirement

con-straint (19) is continuously binding, that is, ¯E= F Because

equityispredetermined,banklendingforinvestmentmustadjust

tosatisfythecapitalrequirement:

regardlessofwhether isendogenousornot.Weassumethat

con-straint(29)iscontinuouslybinding,duepossiblytoheavypenalties

orreputationalcostsassociatedwithdefaultonregulatory

require-ments,asnotedearlier

With(29)determininginvestment,Eq.(6)isnowsolvedforthe

lendingrate:

iL=h−1



¯E 

wherea=0forsimplicity.Theinterestrate-settingcondition(17)

isnowusedtosolvefortheriskpremium:

L= i

L

εLiR −1= 1

εLiR h

−1



¯E 

Collateralthereforeplaysnolongeradirect roleindetermining

theriskpremium;Eq.(18)servesnowtodeterminetheeffective

collateralrequired,thatis,coefficient.Ofcourse,forthesolution

tobefeasiblerequires<1,whichweassumeisalwayssatisfied

Thus,wecontinuetoassumethatcreditrationingdoesnotemerge

Inadditiontothefinancialequilibriumcondition(31),whose

solutionnowdependsontheregulatoryregime,macroeconomic

equilibriumrequiresequalitybetweensupplyanddemandinthe goodsmarket.Using(29),thisconditiontakesnowtheform:

Ys(P;iR,A)=˛1N

d(P;iR,A)

P −˛2εDiR+˛3



FH 0

P



whosesolutiondependsalsoontheregulatoryregime

Withabindingcapitalrequirement,thecapitalbufferisunity, andbecausef(1)=1,thedepositrate-settingconditionis(15).Thus, thebankcapitalchannel,asidentifiedintheprevioussection,does notoperate.However,theadjustmentprocesstoshockscontinues

todependinimportantwaysontheregulatoryregime;forclarity,

weconsiderthemseparately

4.1 Constantriskweights MacroeconomicequilibriumundertheBaselIregimeisnow illustratedinFig.3.Asbefore,thesoutheastquadrantshowsthe positiverelationshipbetweenoutputandprices.From(29),and with constantatFF,investmentandpricesareinverselyrelated,

asshowninthesouthwestquadrant.Eqs.(30)and(31)alsoimply

anegativerelationshipbetweeninvestmentandtheriskpremium,

asdisplayed in the northwest quadrant Because both the risk weightandinvestmentandindependentoftheriskpremium,the goodsmarketequilibriumcondition,shownascurveG3G3inthe northeastquadrant,is vertical.Thefinancial equilibrium condi-tion,shownascurveF3F3,hasnowapositiveslope,givenby(see AppendixA):

dL

dP



B,FF

I

=− 1

εLiR h

−1 

¯E

P2 R



whereBstandsfor“binding.”

Intuitively,thereason whyFFispositivelyslopedisbecause higherprices nowreduce realinvestment(asimplied by(29)), whichinturncanonlyoccurifthepremiumincreases.The equi-libriumobtainsatpointsE,H,J,andD.Graphically,F3F3issteeper

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Fig 4. Negative supply shock with binding capital requirements (Basel I regime).

thelarger Ris,sothat∂[dL/dPB,FF

I ]/∂ R>0.Allelseequal,the higher Ris,thelargertheeffectofanyshockthatleadstoashift

inthefinancialequilibriumconditionontheriskpremium,andthe

smallertheeffectonprices

AsshowninFig.4,anegativesupplyshockleadstoaninward

shiftofthesupplycurve(asbefore),butthishasnodirecteffecton

thepremiumattheinitiallevelofprices,incontrasttothecaseof

nonbindingrequirements.Thus,F3F3doesnotshift.Excessdemand

ofgoodsrequiresanincreaseinpricestoclearthemarketandG3G3

shiftstotheright.Theincreaseinpriceslowersinvestment,andthis

mustbeaccompaniedbyanincreaseintheriskpremium.Theprice

hikealsolowersconsumption,throughanegativewealtheffect

Thus,theadjustmenttoanegativesupplyshockentailsbothan

increaseinpricesandareductioninaggregatedemand.Thenew

equilibriumpositionisatpointsE,H,J,andD.Theriskpremium

isthusunambiguouslyprocyclical(dL/dA<0)

Toanalyzetherole ofthecapitalregimeinthetransmission

processofthisshock,recallthatwithabindingrequirementthe

depositrate-setting condition(16)becomesindependentof the

capitalbuffer.However,ascanbeinferredfrom(29),thehigher

therisk weight(andthecapital adequacy ratio), thelargerthe

dropininvestmentandlending;thesmallerthereforethe

adjust-mentinpricesrequiredtoequilibratesupplyanddemand.Thus,

the“capital channel”operates now through investment,rather

thanconsumption.Atthesametime,however,a largerdropin

investmentmustbeaccompaniedbyalargerincreaseintherisk

premium.Formally,itcanbeshownthatthegeneralequilibrium

effectisd2L/dAd R>0

4.2 Endogenousriskweights

UndertheBaselIIregime,theendogeneityof precludesthe

useofafour-quadrantdiagramtoillustratethedeterminationof

equilibrium;itisnowshowninasinglequadrant,inFig.5.The

determinationofthefinancialequilibriumconditionF4F4follows

regime).

thesamelogicasbefore;itthereforehasapositiveslope,given nowby(seeAppendixA):

dL

dP



B,FF

II

=− 1

˙4

1

εLiR h

−1 

¯E

P2 R



where ˙4>0if  isnottoolarge,and˙4<1.A comparison

of(33)and(34)showsthatthisslopeissteeperthanunderBasel

I.Intuitively,thereasonisthatnowthedirect,positiveeffectof

anincreaseinpricesonthepremium(whichvalidatesthefallin realinvestment,asnotedearlier),iscompoundedbyanincrease

intheriskweight.Thus,allelseequal,shockswouldnowtendto havelargereffectsontheriskpremium,andmoremutedeffects

onprices,thanunderthepreviousregime

Thegoodsmarketequilibriumcondition,however,isnolonger vertical;because␴ dependsonL,itcanbedisplayedasanegative relationshipbetweentheriskpremiumandthepricelevel,denoted

G4G4inFig.5,withslope

dL

dP



B,GG

II

4

YPs+˛1

P2(Nd−PNd)+˛3



FH 0

P2



+ ¯E

P2 R

, (35) where 4<0

ThereasonwhyGGisdownward-slopingisnowdifferentfrom thenonbindingcase:hereanincrease inthepricelevellowers realinvestment,as impliedbythebindingconstraint(29);this mustbevalidatedbyanincreaseintheriskpremium.However, thepriceincreasealsolowersconsumptionandstimulatesoutput (forreasonsoutlinedearlier);inturn,thisrequiresafallintherisk premiumtostimulateinvestmentandrestoreequilibriumbetween supplyanddemand.Thefigureassumesthatthesecondeffect dom-inatesthefirst(orequivalentlythat isnottoolarge),soG4G4

hasindeedanegativeslope.Thus,thegoodsmarketequilibrium conditionisnowlesssteep;allelseequal,shockswouldtendto havemoremutedeffectsontheriskpremium,andlargereffects

onprices,thanunderBaselI.Becausetheslopesofthetwocurves areaffectedinoppositedirectionbyaswitchfromBaselItoBasel

II,itcannotbeascertainedaprioriwhethershockswouldtendto havelargereffectsontheriskpremium,asunderthenonbinding case—whereonlyGGwasaffectedbyaswitchinregime

Trang 10

Fig 6.Negative supply shock with binding capital requirements (Basel II regime).

Fig.6illustratestheimpactofanegativesupplyshock.Curve

G4G4shiftstotherightandtheequilibriumischaracterizedbya

higherriskpremiumandhigherprices,asinFig.4.Thus,theshock

isprocyclical,asunderBaselI.ButeventhoughonlytheGGcurve

shifts(asisthecaseunderBaselI),theinitialpositionofFFmatters

forthefinaloutcome.Thus,whetherBaselIIismoreprocyclicalor

lessprocyclicalthanBaselIcannotbedeterminedunambiguously

Insum,withbindingcapitalrequirements,anegativesupply

shockisunambiguouslyprocyclicalandunderBaselI.Thehigher

theriskweight Ris,thestrongertheeffectofashockontherisk

premium.TheshockisalsounambiguouslyprocyclicalunderBasel

II;However,whetherasupplyshockentailsmoreprocyclicalitywith

respecttoBaselIinthebehavioroftheriskpremiumcannotbe

ascertainedapriori

5 Concluding remarks

Thepurposeofthispaperhasbeentoanalyzetheprocyclical

effects of BaselI- and BaselII-type capital standards in a

sim-plemodelthatcapturessomeofthemostsalientcredit market

imperfectionsthatcharacterizemiddle-incomecountries.Inour

model,capitalrequirementsareessentiallyaimedatinfluencing

bank decision-makingregarding exposuretoloandefault They

affectboththequantityofbanklendingandthepricingofbank

deposits.Thebankcannotraiseadditionalequitycapital—aquite

reasonableassumptionforashort-termhorizon.Thedepositrate

is sensitivetothesize ofthebuffer, througha signalingeffect

Well-capitalizedbanksfacelowerexpectedbankruptcycostsand

hencelower fundingcostsfromthepublic Wealsoestablisha

linkbetweenregulatoryriskweightsandthebank’sriskpremium

underBaselII;thisisconsistentwiththefactthatinthatregime

theamountofcapitalthatthebankmustholdisdeterminednot

onlybytheinstitutionalnatureofitsborrowers(asinBaselI),but

alsobytheriskinessofeachparticularborrower.Thus,capital

ade-quacyrequirementsaffectnotonlythelevelsofbanklendingrates,

andthusinvestmentandoutput;theyalsoaffectthesensitivityof

theseratestochangesinoutputandprices

Ouranalysisshowedthatdifferenttypesofbankcapital

regula-tionsaffectindifferentwaysthetransmissionprocessofanegative

supplyshocktobankinterestrates,prices,andeconomicactivity

Asdiscussedintheexistingliterature,andregardlessofthe regu-latoryregime,capitalrequirementscanhavesizablerealeffectsif theyarebinding,becauseinordertosatisfythembanksmaycurtail lendingthroughhikesininterestrates.However,wealsoshowed that,evenifcapitalrequirementsarenotbinding,a“bankcapital channel”mayoperatethroughasignalingeffectofcapitalbuffers

ondepositrates.Ifthereissomedegreeofintertemporal substitu-tioninconsumption,thischannelmaygeneratesignificanteffects

ontherealeconomy

Severalpolicylessonscanbedrawnfromouranalysis.First, reg-ulatorsshouldpaycarefulattentiontotheimpactofriskweightson bankportfoliobehaviorwhentheyimplementregulations.Second, capitalbuffersmaynotactuallymitigatethecyclicaleffectsofbank regulation;inourmodel,capitalbuffers,byloweringdepositrates, areactuallyexpansionary.Thus,ifcapitalbuffersareincreased dur-inganexpansion„withtheinitialobjectiveofbeingcountercyclical, theymayactually turn out tobe procyclical.This is an impor-tantconclusion, given theprevailing viewthat counter-cyclical regulatoryrequirementsmaybeawaytoreducethebuildupof systemicrisks:ifthesignalingeffectsofcapitalbuffersare impor-tant,“leaningagainstthewind”maynot reducetheamplitude

of thefinancial-business cycle.27 A more detailed studyof the empiricalimportanceofthesesignalingeffects,buldingperhaps

onFonsecaetal.(2010),isthusapressingtaskformiddle-income countries.Moreover,thepossibility ofasymmetriceffectsshould alsobeexplored;forinstance,ahighcapitalbufferingoodtimes mayleadhouseholds(asownersofbanks)toputpressureonthese bankstogeneratemoreprofits,inordertoguaranteea“minimum” returnonequity;bycontrast,thesignalingeffectalludedtoearlier maybestrengthenedinbadtimes

Ouranalysiscanbeextendedinseveraldirections.Oneavenue couldbe to extend the bank capital channel as modeled here

byassumingthat a largecapital bufferinducesbanksnot only

toreducedepositrates(asdiscussedearlier)butalsotoengage

inmore risky behavior, which maylead themto relaxlending standardsandlowerthecostofborrowinginordertostimulate thedemandforloansandincreaseprofits.However,becausethis wouldleadtoanexpansionaryeffectoninvestment,itwouldgo

inthesamedirectionastheconsumptioneffectalludedtoearlier Thus,ourresultswouldnotbeaffectedqualitatively

Aseconddirectionwouldbetorelaxtheassumptionof port-folioseparation,forinstancebyintroducinga“joint”costfunction fortheproduction/managementofloansanddeposits.Inthatcase, equilibriumconditionsforprofitmaximizationwouldbe interde-pendent;bothbankrateswoulddependonthecapitalbuffer,and thiswouldsubstantiallyaffectthewaythebankcapitalchannel operatesinthemodel.Alternatively, itcouldbeassumed, asin Agénoretal.(2009),thatbankcapitalhasnoeffectonthedeposit ratebutinsteadreducestheprobabilityofdefault(byincreasing incentivesforbankstomonitorborrowers)andthatexcess capi-talgeneratesbenefitsintermsofreducedregulatoryscrutiny.As shownthere,asimilarambiguityinrankingtheprocyclicalityof BaselIandBaselIImayemerge

InAgénoretal.(2009),wehavealsoembeddedthefinancial featuresofthepresentmodelinadynamicoptimizingframework,

inlinewithothercontributionssuchasMarkovic(2006),Aguiar andDrumond(2007),andMehandMoran(2010).Thisallowsus

... and Montiel (2008a) , in terms of the value of the beginning -of- period

Trang 8< /span>

out-put,asperthedefinitionabove—orcountercyclical(dL/dA>0).This... outlater.WealsofocusatfirstonthemovementleadingtopointE Thefirsteffectoftheshockisofcourseadropinoutput;as showninthesoutheastquadrant,thesupplycurveshiftsinward, withoutput(attheinitiallevelofprices)droppingfromHtoM.The...

Inthecasewheref>0(and˛2>0),theimpactoftheregulatory

regimeonthedegreeofprocyclicalityoftheriskpremiumcanbe

formallyassessedbycalculatingthederivativeoftheequilibrium

outcomedL/dAwithrespectto␴,thatis,d2L/dAd ,inamanner

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