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
Trang 1journal 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
Trang 2overthebusinesscycle,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−˛)
Trang 3areinverselyrelatedtotheeffectivecostoflabor,(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
Trang 4capitalbuffer, 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
Trang 5inpartial 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 6Table 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
where1<0if ˛2 is not toolarge(seeAppendix A)and, with (L)= Rinitially,
dL dP
NB,GG
II
=
1
2
dL dP
NB,GG
I
where2<0and2>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 7Fig 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 8out-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
Trang 9Fig 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) where4<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 10Fig 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