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Journal
of
Economic
Dynamics
&
Control
journal homepage: www.elsevier.com/locate/jedc
Optimal
bankruptcy
code:
A
fresh
start
for
some
R
Grey
Gordon
IndianaUniversity,DepartmentofEconomics,100S.WoodlawnAve.,Bloomington,IN47405,UnitedStates
a
r
t
i
c
l
e
i
n
f
o
Articlehistory:
Received14August2017 Revised9October2017 Accepted22October2017 Availableonline27October2017
JELclassification:
D14 D52 D91 E21 K35
Keywords:
Bankruptcy Life-cyclemodels Incompletemarkets
a
b
s
t
r
a
c
t
Whatistheoptimal consumerbankruptcylaw?Ianswer thisquestionusingan incom-pletemarketslife-cyclemodelwithaplannerwhocanchoosestate-contingentbankruptcy costs.Ideveloptwomaintheoreticalcharacterizations. First,wheneverdebtdischargeis allowed,it shouldoccur withoutcost.Second,bankruptcyshouldalwaysbeallowedfor highly-indebtedhouseholds.Quantitatively,theoptimalpolicycangenerateawelfaregain aslargeas11.6%.However,attractiveinformaldefault,asymmetricinformation,andmoral hazardcanreducethewelfaregaintoaslittleas0.7%.
© 2017ElsevierB.V.Allrightsreserved.
1. Introduction
Bankruptcypolicyvariesgreatlybytimeandlocation.InmanyEuropeancountries,thereislittletonodebtforgiveness. BankruptcylawsintheUnitedStates,ontheotherhand,arewidelyconsideredpro-debtor.Moreover,viewsontheproper amountofdebtforgivenesshavechanged dramaticallyoverthelast two hundredyears.Inthe U.S.,debtors’prisons have beenreplacedwitharelativelyswiftbankruptcyprocess,which,untilrecently,offeredanear-completedischargetoalmost everyone.In2005, theBankruptcyAbusePreventionandConsumerProtection Actrestrictedthisnear-completedischarge toonlythosewithbelow-medianincome,forcingabove-medianincomehouseholdstopayalltheirdisposable income(in thespecificsensedefinedbythelaw)forfiveyears.1 Whichofthemanypossiblebankruptcylaws—rangingfromcomplete dischargeforalltonodischargeatall—isbest?
Toanswer this question, Iuse an incomplete markets life-cycle model of bankruptcy andallow a planner to choose state-contingentbankruptcypenalties.The plannerspecifieswhethera householdmayfileforbankruptcy, anyassociated
R IthankKartikAthreya,SatyajitChatterjee,DaphneChen,HalCole,BulentGuler,AaronHedlund,JuanCarlosHatchondo,AubhikKhan,DirkKrueger,
AmandaMichaud,VictorRíos-Rull,Pierre-DanielSarte,MichèleTertilt,JuliaThomas,andEricYoung,aswellasanonymousreferees.Ialsothankconference participantsfromtheEuropeanMeetingoftheEconometricSociety2014,ComputinginEconomicsandFinance2014,MidwestMacro2013and2014,and aUIUCmini-conferencein2014,aswellasseminarparticipantsatFloridaStateUniversity,theOhioStateUniversity,andPurdueUniversity.
E-mailaddress:[email protected]
1Robeetal.(2006)documentboththehistoricalandgeographicalvariationinbankruptcylaws,andColeman(1974)documentsthevariationinU.S. bankruptcylawsovertime.AsWangandWhite(2000)summarize,“theUnitedStatesisextremelyunusualinhavingveryprodebtorbankruptcylaws” (p. 255).FordetailsontheBankruptcyAbusePreventionandConsumerProtectionAct,seeWhite(2007).
filingcostsandearningsrestrictions,andhowlongabankruptcyremainsonahousehold’screditrecord.Inchoosingthese penalties,theplannerfacesatrade-off betweenimprovingcreditandaddingstate-contingencytodebtrepayment.
Ianalyticallycharacterizetheplanner’soptimalpolicyforabroadclassofutilityfunctions,socialwelfarefunctions,and labor efficiencyprocesses under full information.I find two main results.First, whenever the optimal policy givesdebt forgiveness,itisgivenwithoutcost,a“freshstart.” Thefreshstartintheoptimalpolicydeviatessubstantiallyfromcurrent U.S.policyinthattherearenofilingcostsandabankruptcyfilingneverimpactsahousehold’screditrecord.Second,Ifind that bankruptcyshould always be allowed insome states.In particular,ifa householdcannot repaytheir debtor would otherwiseprefertoinformallydefault,bankruptcyshouldbeallowed.Asacorollaryofthisresult,anaturalborrowinglimit economy—aneconomywherehouseholdshavemaximalcommitmenttorepaytheirdebt—issuboptimal.
Quantitatively,Ifindtheoptimalpolicyproducesaconsumptionequivalentwelfaregainof11.6%relativetoaneconomy calibrated to match the U.S. when informal default is unattractive and there is full information. It doesso by typically allowingbankruptcyforthosewithbadpersistentshocksandhighdebtlevelsbutforbiddingitotherwise.Undertheoptimal policy,householdsaccumulatedebtequaltohalfofaverageearningsbytheirmid-30sandonlybeginsavingforretirement intheirmid-40s.Theoptimalpolicyresultsinasmallincreaseindefaultrates,afifteen-foldincreaseindebt,and50%lower interestratesandcharge-off rates.
Whilethegainsfromtheoptimalbankruptcyarequantitativelylarge,thenumbersabovewerecalculatedassumingcostly informaldefault,fullinformation,andfullabilitytounderstandacomplicatedbankruptcylaw.Thelastoftheseassumptions seems tomatterquantitatively little:Asimplerulegeneratesawelfaregain of10.6%,onlyonepercentagepointlessthan the11.6%fromtheoptimalrule.Theassumptionoffullinformationmattersmuchmore.Specifically,whenhouseholdsare allowed to reduce their earnings ina wayunobservableto bankruptcycourts, accessto bankruptcyis severelyrestricted and the welfare gain obtained by the optimalpolicy fallsto 5.5%. This gain is not much more than the 5.4% produced bya naturalborrowinglimiteconomy. Whileasymmetricinformationwithmoral hazardsignificantly impairstheoptimal policy,limitedcommitment intheform ofan attractive outsideoptioncan be evenworse. Inparticular, whenthe value ofinformal defaultis madeaslargeasthe theory allows,the optimalpolicy producesa welfaregain of only0.7% under both fullandasymmetricinformation.Thislast resultsuggeststhatoptimalpolicy—whenit hascontrolover thevalueof informaldefault—shouldmakeitasunattractiveaspossible,aclaimIproveunderfullinformation.
1.1. Relatedliterature
Thispaperispartofa largequantitative literature,surveyedby Livshits(2015),thatinvestigates consumerbankruptcy lawandits implicationsforconsumption,credit,andwelfare.Policy evaluationshavebeendone bymodeling specific re-formsorconsideringmoretheoreticalexercises,suchaseliminatingbankruptcy.2 Most,thoughnotall,oftheseexperiments havebeenconductedundertheassumptionsoffullcommitment(inthesenseofbankruptcybeingtheonlydefaultoption) andfullinformation.Theoverridingthemeofthisliteratureisthatharsherbankruptcylawsalmostalwaysimprovewelfare, eventothepointthateliminatingbankruptcygreatlyimproveswelfareintheabsenceofshockstohouseholdexpenditures. The presentpaperhelpstointerpret theseresults bytheoretically andquantitatively characterizingthe optimalpolicy. Thecalibratedmodelreproducesthefindings oftheliteraturethateliminating bankruptcyproduces alarge(5.4%)welfare gain relativeto theU.S.when thereisfull commitmentandfull information.However,the theoreticalresultsshow there isalwaysabetterpolicyallowingbankruptcyinsome states,suchasstateswhererepaymentisimpossible.Quantitatively, the optimalpolicy underfull commitment andfull information produces a welfare gain of 11.6%. This showsthat while thegainfromeliminatingbankruptcyislarge(astheliteraturehasrepeatedlyfound),thereisafarbetteroptionallowing bankruptcy. Moreover,themeans by whichthislarge gainis achieved—defaultconcentrated amongthosewiththe worst persistentshocksandcostlessbankruptcyconditionalondefault—suggestpathsforpolicygoingforward.
Byanalyzing the optimalpolicy inthe face oflimitedcommitment,the paperalso contributesto andhelpsinterpret a literature thathasallowed formultiple defaultoptions.3 The mostcloselyrelatedisChatterjeeandGordon (2012) that quantitatively shows(1) eliminating bankruptcyimproves welfare evenwhen households mayinformally defaultand(2) making theinformal defaultoptionascostly aspossible improveswelfare.The presentpapershowsthat even whenthe firstfinding holds,theoreticallyit isalways optimaltoallowsome bankruptcy.In fact,allowing bankruptcyifandonly if householdswouldotherwiseinformallydefaultachievesthesamewelfare(quantitatively) asthefull optimalpolicywhen informaldefaultisveryattractive.Asfortheirsecondfinding,theresultsconfirmittheoreticallyandquantitatively: Theo-retically,theplannershouldmakeinformaldefaultasunattractiveaspossible;quantitatively,theoptimalpolicycanachieve awelfaregainofonly0.7%ifinformaldefaultisveryattractive.
This paper is also connected to a theoretical literature that can be divided into two branches. The first, beginning with Kehoe and Levine (1993) andcontinued by Kehoe and Levine (2001; 2006), Kocherlakota(1996), and Alvarez and Jermann(2000) has focused oncomplete markets withlimited commitmentinthe formof a participationconstraint. In
2This approach hasbeen followed by Athreya (2002), Athreya etal. (2009b), Athreya etal. (2009a),Liand Sarte (2006), Livshits etal. (2007), Chatterjeeetal.(2007),ChenandCorbae(2011),ChatterjeeandGordon(2012)andGordon(2015)andothers.
theseeconomies,equilibriaareParetoefficient.The secondbranchhaslookedatasymmetricinformationwithmoral haz-ard.Inthisliterature,efficiencytypicallyrequiresthataninverseEulerequationholds,aconditionthatisoftenimpossible whenhouseholdshaveunimpededaccesstosavingandborrowingatarisk-freeprice.4BizerandDeMarzo(1999),Bisinand
Rampini(2006),andGrochulski(2010) allshow thatbankruptcycan beusedto maketheinverseEulerequation holdby impedingthisfree-flowofcredit.
Akey distinction betweenthispaperand thetheoretical literature is thetype of debtcontractsused. The theoretical literaturehasemployed Dubeyetal.(2005)(DGS)-styledebtcontractswhereborrowinglimitsare takenasexogenousby agentsandinterest ratesbear aconstant riskpremium.Incontrast,thispaperandthe quantitativeliterature havealmost exclusivelyworkedwithEatonandGersovitz(1981)(EG)contracts.WithEGcontracts,eachlevelofborrowinghasa poten-tiallydistinctpriceandthereisno“borrowinglimit” intheconventionalsensebutinsteadaLaffercurve.
As it turns out, DGS contracts are essential forthe theoretical literature’s results.For instance, a feature common to
KehoeandLevine(2006)andGrochulski(2010)isthat,forthedecentralizedequilibriumtoachievetheefficientallocation, theexogenous(toborrowers)borrowinglimitsmusttakeonveryspecificvalues.5Additionally,theseexogenouslimitsmust, atleastinGrochulski(2010),bedecreasinginwealth(p.366–367).ForbankruptcypolicythatisMarkov,thistypeofpricing requiresDGScontractsratherthanEGcontracts.
AsIestablish inAppendixC, EGcontractshaveatleast fourconceptualandtheoretic advantagesover DGS-style con-tracts.First, DGS contractstypically have multiple equilibria corresponding to various exogenous borrowinglimits while EGcontractsdonot.6 Second,DGS contractsare notnecessarilycompetitive inthefaceoffreeentry.Incontrast,EG con-tractsarepricedtoexactlypreventthistype ofentry.Third,evenfixingtheexogenousborrowinglimit,DGScontractscan havemultipleequilibria,someofwhichcanhaverisk-freeratesandnoequilibriumdefaultandotherswithriskyratesand equilibriumdefault.Fourth, whentherearemultipleequilibriaofthissort, itisoftenpossibleforfirmstoenterandmake strictlypositiveprofits.Again,EGcontractsarenotsubjecttotheseissues.
The cost of usingEG contracts is the non-lineardebt pricing that makes budget constraints much more complicated andtheoretical results harderto obtain. Moreover, itlikely makes implementing a constrained efficientallocation of the typeinGrochulski(2010) impossible.7 Soinsteadthispaperproceedsintheother direction,startingfromadecentralized equilibriumandworkingtowardsefficiency.
2. Model
Thelife-cyclebankruptcymodelisessentiallyLivshitsetal.(2007)augmentedtohaveelasticlaborsupply(withinelastic asaspecialcase)butwithoutexpenditureshocks,i.e.,directshockstoahouseholdsnetworth.8
2.1. Modelsetup
TheeconomyispopulatedwithacontinuumofhouseholdswholiveforatmostTperiods.Thehouseholdlaborefficiency
eisstrictlypositiveandfollowsafinite-stateMarkovchain
πee
|t thatis age-dependent.Newbornhouseholdsdrawefrom adistributionπe
.Marketsare incompletewithhouseholdsonlyhavingaccesstoabond a∈Awitha<0beingunsecureddebt(negative networth)anda≥0beingsavings.Aisafinitesetcontainingnegativeandpositiveelements,aswellaszero.Forsimplicity, Iassumehouseholdsmaynotdefaultonsavingsa≥0.Newbornhouseholdshavea=0.
Householdshave a bankruptcy flag hindicating whether a bankruptcy is on their credit record, h=1, ornot, h=0. All households beginlife withh=0. When a householdfiles forbankruptcy or has a bankruptcy record, it is assumed thatthey maynot borrow. Thisrestrictionis fortractability,andit meansthat onlyone bankruptcylawisneeded(since householdswillnotdefaultona≥0)ratherthantwo.Thisassumptioniscommonintheliteratureandcapturesanempirical observationduetoMusto(2004)thatcreditaccessislimitedwhilearecordofbankruptcyremainsandincreasesassoonas itisremoved.However,nothinglegallypreventscreditorsfromlendingtobankrupthouseholds,andthelackofcreditmay reflectthereactionofcreditorstoinformationcontainedinabankruptcyrecord.Iwillrevisitthispointinthediscussionof
Proposition3.
4Incommonlyusednotation,efficiencydictates (u(c)) −1=(β(1+r)) −1E[(u(c)) −1](aresultduetoRogerson,1985).Jensen’sinequalitythenimplies
u(c) =β(1+r) Eu(c) .
5SeeProposition3onp.13inKehoeandLevine(2006)andtheproofofProposition2onp.363inGrochulski(2010).
6Inthispaper’sframework,theequilibriumisuniqueuptoatie-breakingrule.Ininfinite-horizonproblems,AuclertandRognlie(2014)haveshown uniquenessundertheassumptionofi.i.d.shocksorpermanentexclusionfromcreditmarketsfollowingdefault.
7ThecreditlimitsinGrochulski(2010)induceaveryspecificamountofborrowing(seeequation35onp.363).InanEGframeworkwithdiscrete shocks,debtpricesarestepfunctionsandsothereareimplicitrestrictionsonborrowingquantities.
Preferencesareadditivelytime-separableoverconsumption candlabornwitha discountfactor
β
>0.Laborischosen fromafinitesetN⊂R++,andIassume theperiodutilityfunctionu(c,n) iswell-definedforanyc>0andanyn∈N.The periodutility uiscontinuousandstrictlyincreasing inc—butnot necessarilyconcaveordifferentiable—anddecreasinginn.Additionally,itisunboundedbelowwithlimc↓0u
(
c,n)
=−∞foralln.Havingutilityunboundedbelowisimportantfor thetheoretical results.However,itdoesmeanu(0,n) isnotdefined, andsoIrequirehouseholdschoosec>0(thechoice setisstill compactbecauseais restrictedto lieina finiteset).Additionally,Iallowforpsychiccostsofdefault,κ
(e)≥0, thatdependonhouseholdefficiency.Thesecostsapplyifeitherformaldefault(bankruptcy)orinformaldefault(theoutside optiondiscussedbelow)occurs,andtheyareassumedinvarianttoplannerpolicy.Ahousehold’sstateis(a,e,t,h). Thepriceofadiscountbondwithfacevalue a isqt(a,e). Forsavings,a≥0,default isnotallowed, andsothepriceforsuch abondissimplyequaltotherisk-freerateoftransferring resourcesacrosstime,
¯
q<1,whichItaketobeexogenousfortractability.Fordebt,a<0(whichimpliesh=0),creditorsexpectarepaymentrate
pt(a,e).Consequently,ano-arbitrageconditionhas
q t
(
a , e)
=q ¯p t(
a , e)
. (1)Whentherepaymentratept islow,soisthepriceqt,whichimpliesahighinterestrate1/qt−1.Equilibriumwillrequire that therepaymentrateis consistentwithhouseholddefaultdecisions.Forconvenience, Idefine pt
(
a≥0,e)
=1 sothatqt
(
a,e)
=q¯pt(
a,e)
foralla,e.Bankruptcypolicy isdefinedby theinstrumentsavailabletotheplanner.Specifically,theplannercandoallofthe fol-lowing:
1. Specifywhetherahouseholdisallowedtofileforbankruptcy,Dt
(
a,e,n)
={
0,1}
,ornot,Dt(
a,e,n)
={
0}
. 2. Chargeabankruptcyfilingcostζ
t(a,e,n)≥0.3. Retainabadcreditrecordwithprobability
λt
∈[0,1].Theplannermusteitherforgiveallofahousehold’sdebtornoneofit.However,thisassumptionisnotasstrongasit seemsbecausepartialforgivenessmaybeincorporatedviaalottery.9 Thepoliciesavailabletotheplannercover,asspecial cases,manyofthetypesofpenaltiesthattheliteraturehasusedtomodelbankruptcy.
Householdsmayalways informallydefault by choosingan outside optiondeliveringVO
t
(
a,e;γ
)
inlifetimediscounted utility terms whereγ
isa policy instrument ofthe planner.10 The outside optionis meant to representthe bestoption consumers havefor dealingwith debtother than repaying it orobtaining a discharge, andthe planner mayhave some controlover howattractivetheoutsideoptionis.Forexample,debtcollectionmethodsareextensivelyregulatedby law— includingwhen andhowoftendebt collectorscan makephonecalls, informationdebtcollectors mustprovide,andeven whatmaybewrittenonenvelopes—andabankruptcyreformcouldbepairedwitharevisionoftheselaws.11However,the planner’sinfluencemaybelimited.Technology,whichDrozdandSerrano-Padial(2017)haveforcefullyarguedisofessential importance inthedebt collectionindustry,isone potentiallylimitingfactor. Anotherisa household’sabilitytoleave the country.12Toflexiblycapturetheplanner’sabilityorinabilitytocontroltheoutsideoption’sattractiveness,Iassumeγ
must bechosenfromaset,whichItaketobefinite.Notethatif
isasingleton,theplannertakesVO asgivenandcanonly reformbankruptcypolicy.
Imakethreekeyassumptionsregardingtheoutsideoption.First,whenitischosen,thecreditorgetsnothing.Whilenot withoutlossofgenerality,recoveryratesondefaulteddebtcanbeaslowas12–14%netofcollectioncosts(Chatterjeeand Gordon,2012).Second,VO
t
(
a,e;γ
)
islessthanorequaltoan“autarky” valueVtA(
a,e)
forallγ
∈.Ideviatefromtheusual definition of autarky to allow for savings at the risk-free rate andapply a psychic cost of default in the first period of autarky.Thatis,VO
t
(
a,e)
≤VtA(
a,e)
:=Xt(
0,e)
−κ
(
e)
whereX t
(
a, e)
=maxa∈A,n∈Nu(
c, n)
+β
e
π
ee|tX t+1(
a , e)
s.t. c +q ¯a =en +a, c > 0, a ≥0 (2)
with XT
(
a,e)
:=maxn∈N,en+a>0u(
en+a,n)
. Third, VtO(
a,e;γ
)
is invariant to the bankruptcy policy instruments Dt,ζ
t,λ
t. Whilethismightseemrestrictive,itneednotbe.Forinstance,ifchoosingtheoutsideoptionresultsinbeingpermanently barredfromcreditmarkets,thentheoutsideoptionisindependentofbankruptcypolicy.2.2. Householdproblem
Fortheremainder ofthepaper, Iwillsuppressthedependenceofvalue functions, policies,andpricesonthe planner policiesexceptwhennecessaryforclarity.Giventhepolicyinstrumentsandprices,thevaluefunctionofahouseholdwith
9Forinstance,supposeonehadei.∼i.d.
U[1,1+σ]discretized.Forσ≈0,theearningsriskisnegligible,butacutoff ¯e∈[1,1+σ]suchthatDt(a,e,n) =
{0,1}ifandonlyife≤e¯causesafraction ( e¯−1) /σofthedebttobeforgiven.Thisargumentcanbeextendedtoanyefficiencyprocessbyincorporating asmalli.i.d.shock.
a,e,tthathasnorecordofabankruptcyis13
V t
(
a, e, h =0)
=maxo,doV tO(
a, e)
+dV tD(
a, e)
+(
1−o)(
1−d)
V tR(
a, e)
s.t. o ∈
{
0, 1}
, d ∈n∈ND t(
a, e, n)
, od =0(3)
wherethevalueofrepayingdebtis
V R
t
(
a, e)
=maxa∈A,n∈Nu(
c, n)
+β
e
π
ee|tV t+1(
a , e , 0)
s.t. c +q t
(
a , e)
a = en +a, c > 0(4)
andthevalueofdefaultingviabankruptcyis
V D
t
(
a, e)
=maxa∈A,n∈Nu(
c, n)
−κ
(
e)
+β
e
π
ee|t(
1−λ
t)
V t+1(
a , e , 0)
+λ
tV t+1(
a , e , 1)
s.t. c +q ¯a +
ζ
t(
a, e, n)
= en, c > 0, a ≥0D t
(
a, e, n)
={
0, 1}
.(5)
Notethat since bankruptcy policy conditionson labor, to obtain a dischargethe householdmust chooselabor such that
Dt
(
a,e,n)
={
0,1}
.Ifahousehold’sbudgetconstraintwouldbeemptyuponchoosingtorepay,theymustchooseeitherthe outsideoptionor,iftheplannerletsthem,bankruptcy.Thevalueofhavingabankruptcyrecord,h=1,is
V t
(
a, e, h =1)
=maxa∈A,n∈Nu(
c, n)
+β
e
π
ee|t(
1−λ
t)
V t+1(
a , e , 0)
+λ
tV t+1(
a , e , 1)
c +q ¯a = en +a, c > 0, a ≥0. (6)
NotethatIdonotallow householdsinbadstandingaccessto anoutsideoption.Thisiswithoutlossofgenerality(wlog) becauseVO
t
(
a,e)
islessthanthevalueofautarkyandVt(
a,e,h=1)
isgreaterthanit.2.3.Equilibrium
Equilibriumforagivensetofpolicyinstruments,Dt,
λ
t,ζ
t,γ
andarisk-freepriceq¯isa setofpolicies,ct,nt,at,dt,ot, valuefunctionsVt,pricesqt,andrepaymentratesptsuchthat1.Householdsoptimizetakingpricesasgiven.
2.Thepricescheduleqtisgivenbynoarbitrage:qt
(
a,e)
=q¯pt(
a,e)
. 3.Repaymentratespt areconsistent:p t
(
a , e)
=e
π
ee|t(
1−max{
d t+1(
a , e)
, o t+1(
a , e)
}
)
. (7)2.4.Planner’sproblem
Theplannersolves
maxζ,λ,D,γa,e,t
α
t(
a, e)
V t(
a, e, h =0)
s.t. D t
(
a, e, n)
∈{{
0, 1}
,{
0}}
,λ
t∈[0, 1],ζ
t(
a, e, n)
≥0,γ
∈∀
a, e, n, t(8)
where
αt
(a,e)≥0istheweightplacedontype(
a,e,t,h=0)
.143. Theoreticalresults
Thissectioncharacterizes theoptimalpolicytheoreticallyunderfullinformation.Tosimplifytheproofs,householdsare assumedtorepaywhenindifferentbetweenbankruptcyandrepayment.Ifindifferentbetweenbankruptcyandtheoutside option,theyareassumedtofileforbankruptcyifitisanoption.AllproofsarerelegatedtoAppendixA.
Beforecharacterizingtheoptimalpolicy,itisessentialtoestablishthatequilibriumexistsgivenplannerinstruments.The onlywaythiswouldnotbethecaseisifasolutiontothehouseholdproblemdidnotexist.However,sincehouseholdsonly haveafinitenumberofchoices, andtheyalwayshaveatleastonefeasiblechoice(specifically,neverborrowingorsaving), thisisguaranteed.
Proposition1. Foranypolicychoiceoftheplanner,anequilibriumexists.
13 Toreducenotation,Itreatbankruptcyandrepaymentasfeasibleoptions.Ifbankruptcyisnotfeasible,thenthevaluefunctionshouldbereformulated withoutreferencetoVDandsimilarlyforVR.Additionally,defaultoptionsareonlyavailableifa<0.Tohandlethecaseoft=T,takeV
Proposition 2 shows that the outsideoption can be madeirrelevant: If VO is sufficiently negative, the outsideoption will neverbe chosen inequilibrium. Consequently, the plannercan completelyeliminate equilibriumdefault whenVO is sufficientlylow:ByspecifyingDt
(
a,e,n)
={
0}
foralla,e,n,t,householdsalwayschoosetorepaytheirdebtandthemodel isequivalenttoastandardAiyagari(1994)model.The keytotheproofisthat alowerboundonlifetimeutilitywouldbe violatediftheoutsideoptionwerechoseninequilibriumandwassufficientlyunattractive.Proposition2. Thereexistsa
δ
suchthatVOt
(
a,e)
<δ
foralla,e,timpliestheoutsideoptionisneverchoseninequilibrium.Aprincipaldifficulty incharacterizingbankruptcypolicyisthatimprovementsinVtalsoimproveVtR−1andVtD−1 through
continuationutility.DependingonhowVR
t−1−VtD−1 changes,bankruptcymaybecomemoreattractive,worseningcreditand
potentiallywelfareforaget−2households.However,Lemma1showstheincreaseincontinuationutilityintheVD t−1
prob-lem canbe undone through acommensurate increase in the
ζt
−1 filingcost. This causesthe spreadVtR−1−VtD−1 toneverdecrease,whicheffectivelyallowsVt increasestotrickledowntoyoungerhouseholds.
Lemma 1. Fixsome (a, e,t) with t<Tand supposeVD
t
(
a,e)
is well-defined in thatithas atleast one feasible choice.If thecontinuation utility oftheVD
t
(
a,e)
problem increasesdue to some policy change,VtD(
a,e)
can be held constantby increasingζ
t(a,e,n)foralln.Almost as a corollary of thisresult is that
λ
t>0, i.e., retaining a bankruptcy flag, is unnecessary.Specifically, lower-ingλt
to zero increases continuation utility in the VDt problem, but that effect can be undone via higher filing costs.
Proposition 3 formally establishes that
λ
t=0 isweakly optimal. This result standsin sharp contrast to the U.S. system whereabankruptcyfilingstaysonahousehold’screditreportfortenyears.Proposition3. Foranypolicywith
λ
t>0,thereexistsanotherpolicywithλ
t=0generatingthesameplannerutility.Becauseof theassumptionthat abankruptcyrecord preventsborrowing, setting
λ
t=0both removesinformationand enablesbankrupthouseholdstobeginborrowingagainassoonaspossible.AsmentionedinSection2,nothinglegally pre-ventslendingtobankrupthouseholds,butneverthelesstheyseemtohavelittleaccesstocredit.Ifthisisbecausebankruptcy signalsalackofcreditworthiness,thenretainingthisrecordwouldpresumablybe optimal.Inotherwords,λt
=0—inthe sense ofremoving information—would likelynot be optimalunderasymmetric information.However, thelogic ofsettingλ
t=0—inthesense ofallowing bankrupthouseholds tobeginborrowingquickly—would stillseemto apply.Additionally, whiletheinformation-basedexplanationofreducedcreditpost-bankruptcy isveryintuitive, Athreyaetal.(2012b)argue— basedonresultsfroma modelthat allowsborrowingpost-bankruptcyandasymmetricinformation—thata moreplausible explanationisafull-informationresponsetothepersistentshocksthattriggerbankruptcy.15Consequently,theoptimalλ
t, bothintermsofdroppinginformationandallowingborrowing,maybeclosetozeroevenwithasymmetricinformation.
Fromthispointon,Iwillwlogconsideronlypoliciesthathave
λ
t=0forallt.Aconvenientpropertyofthisisthatthere isnolongeraneedtocarryaroundabankruptcyflag(ashouseholdsarebornwithh=0andnevertransitiontoh=1).So, IwriteVt(a,e)inplaceofVt(
a,e,h=0)
andsimilarlyforthepolicyfunctions,neverreferringtoVt(
a,e,h=1)
oritspolicy functions. Anotherconvenientpropertyisthat thecontinuationutilities oftherepaymentandbankruptcyfilingproblems arenowthesame.Lemma2establishesakeymethodfortheplannertoimproveonanexistingpolicy.Specifically,supposetheplannercan improveVt whileloweringmax{dt,ot}.Inthiscase,two indirectbenefitsaccrue toaget−1households.First,they have improvedcontinuationutility.Second,theyhaveimproveddebtpricing.TheseeffectselseequalincreaseVt−1,VtR−1,andVtD−1.
Byincreasingt−1filingcoststoholdVD
t−1fixed(Lemma1),Vt−1 increasesandmax
{
dt−1,ot−1}
decreases.Thatis,improvedwelfareandcreditforagethouseholdscanbetranslatedintoimprovedwelfareandcreditforaget−1households.Using backwardsinduction,theseimprovementscanbeappliedtoallyoungerhouseholds.
Lemma2. Consideranarbitrarypolicy(
ζ
,D,γ
).Let(
ζ
˜,D˜,γ
)
beapolicythatforsomethasVt˜(
a,e)
higher—relativeto(ζ
,D,γ
)—foralla,e,t˜≥t andmax{dt(a,e),ot(a,e)}lowerforalla,e.Thenthereexistsapolicy(ζ
∗,D∗,γ
)satisfying 1.ζ
t˜∗=ζ
˜˜t andD∗t˜=D˜˜t forallt˜≥t 2. D∗t˜=D˜t forallt˜<t.
thathas higherVt˜
(
a,e)
—relative to (ζ
,D,γ
)—for all a,e,t˜.Moreover, forall a,e,t˜≥t the policies (ζ
∗,D∗,γ
) and(
ζ
˜,D˜,γ
)
inducethesameV˜t
(
a,e)
.Proposition 4showsthatthe plannershould not tiedebtforgiveness tolabor supply.The intuitivereasonis thatonly allowing bankruptcyforsomeamounts oflabor (or,equivalently,earnings)distortsthehousehold’sdecisionandinflicts a dead-weightloss.Specifically,iftheplannerwantsahouseholdtofileinsomestatea,e,t,thenchoosingDt
(
a,e,n)
={
0,1}
foronlysomevaluesofnconstrainsthehousehold’slaborchoiceandreducesVD
t relativetoapolicywithDt
(
a,e,n)
={
0,1}
foralln.Hence,usingDt(
a,e,n)
={
0,1}
forallnimprovesVt(a,e)withoutchangingmax{
dt(
a,e)
,ot(
a,e)
}
=1.Ontheother hand,iftheplannerdoesnotwantahouseholdtofile,hemaysimplysetDt(
a,e,n)
={
0}
forallnwithoutaffectingwelfare orcredit.Consequently,thereisnoreasontotiedebtforgivenesstohoursworked.Proposition4. Forany policy(
ζ
,D,γ
) specifyingDt(a,e,n)varyingin nforsome a, e,t,thereis a policy(ζ
∗,D∗,γ
) withD∗t˜
(
a˜,e˜,n)
invarianttonandVt˜(
a˜,e˜)
higherforalla˜,e˜,t˜.Wlog,InowrestricttheplannertochoosingpolicieswithDt(a,e,n)invariantton.
Anotherdead-weightlossis inducedby havingstrictlypositive filingcosts.Specifically, iftheplannerdoesnot wanta householdtofile,hemaysimplynotletthembysettingDt
(
a,e,n)
={
0}
.Ontheother hand,ifhedoeswantthemtofile, thenthe damage tocreditors,max{dt(a,e), ot(a,e)},is not mitigatedby havingζ
t(a, e, n)>0. Hence,in eithercaseit is optimaltosetζ
t(
a,e,n)
=0.Proposition5establishesthisimportantresult.Proposition5. Considera policy(
ζ
,D,γ
) anddefinet=max{
0}
∪{
t|
∃
a,e,nwithζt
(
a,e,n)
>0}
. Ift>0,thenthere isa policy (ζ
∗,D∗,γ
)—identical to (ζ
, D,γ
) fort>t—withζ
∗ equal to zero thathas higherVt(a, e) for alla,e, t.If under theoriginalpolicy
ζt
(
a,e,nt(
a,e))
>0anddt(
a,e)
=1,thenVt(
a,e)
isstrictlyhigherunderthenewpolicy.Propositions3–5 provide the first main resultof the paper: The planner should eitherallow a household to file for bankruptcy,makingthemaswellofaspossible,orcompletelypreventthemfromfiling.16 Theoptimalpolicythus differs fromU.S.bankruptcypolicy intwokeyways.First,bankruptcyintheU.S.hasbothdirectcostsintheformoffilingcosts andindirectcosts inthe formofexclusion.The optimalpolicy hasneither andallows—inthe truestsense—a freshstart. Second,U.S.lawwithfewexceptionsallowseveryhouseholdtofile.Intheoptimalpolicy,accesstobankruptcyisrestricted. Becausetheplanner’sproblemreducestochoosingDt(a,e,n)∈{{0},{0,1}}foralla,e,t(andanarbitraryn)and
γ
∈, theplanner’s choice setis finite.Moreover, every choice isfeasible asProposition 1 showsan equilibriumexists forany plannerpolicy.Consequently,anoptimalpolicyexists,andthisisestablishedformallyinProposition6.
Proposition6. Anoptimalpolicywith
ζt
(
a,e,n)
=λt
=0foralla,e,n,tandwithDt(a,e,n)invarianttonforalla,e,texists.Intheabsenceoffilingcostsandlabor distortions,bankruptcyisalwaysbetterthanautarky,whichitselfisbetterthan theoutsideoption by assumption.Hence, formal defaultvia bankruptcyisalways preferredin welfareterms toinformal defaultvia the outside option: VD≥VO. Additionally,creditors receive nothingwhen a household defaults irrespective of whetherthedefaultisformalorinformal.Consequently,theplannershouldalwaysallowbankruptcywhenevertheoutside optionwouldotherwisebepreferable.Proposition7formallyestablishesthissecondmainresult.
Proposition7. Supposea policy (
ζ
,D,γ
) hasζ
equalto zero.If Dt(
a,e,n)
={
0}
forsome a,e,t whereVtO(
a,e)
>VtR(
a,e)
orVR
t
(
a,e)
is undefined, then there is another policy (ζ
∗, D∗,γ
) withζ
∗ equalto zero that (1)specifies D∗t˜(
a˜,e˜,n˜)
={
0,1}
wheneverVO
˜
t
(
a˜,e˜)
>V R˜
t
(
a˜,e˜)
orV R˜
t
(
a˜,e˜)
isundefinedand(2)hashigherVt˜(
a˜,e˜)
foralla˜,e˜,n˜,t˜.AtrivialconsequenceofProposition7isthattheplannershould notsetD=
{
0}
forallstates:BecauseVR isundefined ifdebtislargeenough, D={
0,1}
isalways optimalforhighlyindebtedstates.Onereasonthat isinteresting isanatural borrowinglimiteconomy,formallystatedbelow,willneverbeoptimal.Definition. AnaturalborrowinglimiteconomyisaneconomyhavingDt
(
a,e,n)
={
0}
foralla,e,n,twithγ
havingVtO(
a,e)
lowenough,inthesenseofProposition2,tomaketheoutsideoptionirrelevant.Thisdefinition preciselycaptures the notionof anatural borrowinglimit economy inAiyagari (1994).Specifically, (1) householdsalways chooseto repaytheir debt;(2)they can borrow atarisk-free rateup tothe netpresentvalue ofthe worstpossibleearningsstream;and(3)theyneverborrowmorethanthisamount.(Whilelaboriselasticallysuppliedhere, one can have inelasticlabor supply, like inAiyagari, 1994, by making N a singleton.)Because a naturalborrowing limit requiresD=
{
0}
forallstates,evenforstateswheredebtisextremelylargeandhencerepaymentisnotfeasible,itmustbe suboptimal.ThisisformallystatedinCorollary1.Corollary1. Anaturalborrowinglimiteconomyisweakly inferiorto onethatallowsbankruptcywheneverVO
t
(
a,e)
>VtR(
a,e)
orVR
t
(
a,e)
isundefined.This result sheds light on an important question of whether the natural borrowing limit is optimal. This question hasbeen investigatedquantitatively by numerousauthors who, almostwithout exception, finda naturalborrowinglimit
16 Thebang-bangnatureofthisresult isdrivenbythe assumptionsthatthe plannercannotpartiallyforgive debtand cannottransferresourcesto creditors.Whilethelogicofeliminatingdead-weightcostswouldseemtocarryovertoamoregeneralsettingthatrelaxestheseassumptions(sothat,e.g.,
λt=0wouldstillbeoptimal),thebang-bangresultwouldlikelynotsurvive.Asdiscussedinfootnote9,thetheorycanallowforpartialdebtforgiveness,in
significantlyimproveswelfarerelativetoeconomiescalibratedtomatchU.S.statistics.17However,thisresultshowsthatfor awideclassofutilityfunctionsandlaborefficiencyprocesses—evenefficiencyprocesseswherethenaturalborrowinglimit isverylarge—itisalwaysbettertoallowbankruptcyinsomestates.
An important caveat to this and the other results is the absence of general equilibrium (GE) effects, which Li and Sarte (2006) have shown can be importantin large-scale bankruptcy reforms.In the partial equilibriumcontext of this paper,improving value functions(e.g.,by allowing bankruptcyinhighly-indebted states) orincreasing borrowingoptions alwaysimproveswelfare.InGE,thisneednotbethecase:Makinghighly-indebtedstatesunattractiveorlimitingborrowing mayincrease theaggregatecapitalstockandleadtohigherwages,potentiallyimprovingwelfare.Onewaytointerpretthe resultsisby consideringthemasareformcoordinatedwithmonetary policyinordertoachieve afixed realinterest rate andrealwage.
AnotherconsequenceofProposition7isstatedinCorollary2:Optimally,thepolicyresultsintheoutsideoptionnever beingchosen.ThisstandsincontrasttotheU.S.whereinformaldefaultisaregular occurrence.Thebasicintuitionisthat formaldefaultcanreplicateorimproveonwhateverinformaldefaultaccomplishesbothforhouseholdsandcreditors.
Corollary2. Withoutlossofgenerality,theoptimalpolicyhastheoutsideoptionneverchosen.
Whiletheoutsideoptionisneverchosen,itstillplaysacriticalrole.Specifically,itpinsdowninwhichstatestheplanner “must” allowa householdtofile forbankruptcy.The plannerallows bankruptcywheneverVR<VO.IfVO isvery low,this onlyoccursforlargelevelsofdebt.IfVO equalsthevalueofautarky,thisoccursforsmallamountsofdebt.
Infact,Proposition8showsthatiftheoutsideoptionvalueisequaltotheautarkyvalueandtherearenopsychiccosts, the planner can do no better than a zero borrowinglimit economy. The result obtains because bankruptcy is optimally allowed whenevertheoutsideoptionisbetter thanrepayment.Fort=T,there isnoborrowingsothe valueofrepaying debtisstrictlylessthanthevalueofautarky.Consequently,repaymentisworsethantheoutsideoptionandsotheplanner allows bankruptcy for all indebted households.This then causes qT−1=0, resulting inall householdsaged T−1having
value of repaying lessthan the value ofautarky andthe outsideoption. Thisprocess repeats resulting in a full collapse ofthe creditmarket. The resultisqualitatively similarto that inBulowandRogoff (1987) where reputationalone isnot enoughtosustaindebt.
Proposition 8. Suppose there are no psychic costs of default, i.e.,
κ
(
e)
=0. Further, suppose thatfor allγ
∈and all a, e,
t,VO
t
(
a,e)
=VtA(
a,e)
. Then, an optimum features qt(
a,e)
=0 for alla<0and all e,t. Thatis, an optimum features a zeroborrowinglimit.Moreover,if
α
t(a,e)>0foralla,e,t,theneverypolicyproduces Vt(a,e) identicaltothatofazeroborrowinglimiteconomyforalla,e,t.
Proposition 8 shows that if default outside the bankruptcy system is too attractive, nothing can be gained from bankruptcy. Proposition 9complements itby showing that informal defaultshould optimallybe madeasunattractive as possible.The resultholds because(1)bankruptcyisoptimallyusedinplace oftheoutsideoption,soloweringVO hasno directeffectonwelfareand(2)aworseoutsideoptionprovidestheplannerwithadditionallyflexibility aboutwhendebt shouldbeforgiven.
Proposition9. Consideranyoptimalpolicy(
ζ
,D,γ
).Ifthereisaγ
∗∈withVO
t
(
a,e;γ
∗)
≤VtO(
a,e;γ
)
foralla,e,t,thenγ
∗ispartofanoptimalpolicy(
ζ
∗,D∗,γ
∗)havingζ
∗=0.4. Quantitativeresults
The modelisnow broughttothe datatobetter characterizethe optimalpolicy.Thissection assumesfullinformation andfullcommitment(the latterallowingVO tobearbitrarily negative)andsogivesan upperboundonwhatbankruptcy policycanaccomplish.Thenextsectionwillassesshowmuchandinwhatwaysconstraintsontheoptimalpolicymatter.
As inLivshitsetal. (2007), amodel periodis threeyears.Households age1(real age24) to R−1 (real age63) have one labor efficiencyprocess, representing workingagerisk, and householdsaged R(real age 66) toT (real age 84) have another,representingguaranteedretirementincome.TheworkingageprocessisestimatedfromthePanelStudyofIncome Dynamics (PSID) data.As istypical inthe literature, theretirement process hasno risk, anditis calibratedto matchan averagereplacementrate.
4.1. Estimation
ThePSIDdataIuseisfromHeathcoteetal.(2010)andrangesfrom1967to2002.Ithasbeencleanedandprocessedin anumberofways,suchasextrapolationoftop-codedvaluesassumingaParetodistributionanddroppingobservationswith
Table1
PSIDestimation.
First-stageregression GMM
ν1 −0.959 (0.080) ρ 0.969 (0.003) ν2 0.237 (0.020) ση2 0.027 (0.002)
ν3 −0.017 (0.002) ση,21 0.233 (0.004)
N 142,595 σ2
ε 0.065 (0.002)
R2 0.030
implausiblelevelsofconsumption.Inadditiontotheseassumptions,Irestrictthesampletoindividualswithagesbetween 24and63and—fortheefficiencyprocess estimation—requiretheheadand,ifpresent,the“wife” (inthePSIDsense)work acombinedamountofatleast260h.Iassumetheprocesshastheform
loge i,t =
ν
0+ν
1 h +ν
2h 2+ν
3h 3+u i,tu i,t = z i,t+
ε
i,tz i,t =
ρ
z i,t−1+η
i,tz i,1∼N
(
0,σ
η2,1)
,η
i,t∼N(
0,σ
η2)
,ε
it∼N(
0,σ
ε 2)
(9)wherehisageover10,t isageminus 23,andallshocksarei.i.d.Allowingforaseparate varianceofthepersistentshock early in life allows, to some extent, for features that are missingfrom the model such as collegeattainment, race, and gender.Imeasureei,tusingequivalizedtotallaborearnings(theheadandwife’sjointlaborearnings)dividedbytotalhours (headandwife’sjointhoursworked).Conceptually,ei,tcapturestheextraearningsaccruingtoanindividualifhoursworked arescaledinproportiontothecurrentdivision oflaborinahousehold. Ifthe householdhassizeone, itisjusttheusual definitionofthewage.
Thecoefficientsare identified followinga procedure similar toHeathcote etal.(2010). Theage profilecoefficients
ν
1,ν
2,ν
3 areobtainedfromanOLSregressionthatcontrolsfortimeeffects(ν
0 isalsoobtainedfromOLS,butitisusedasanormalizationconstantinthemodel).Theshockprocessparameters
ρ
,σ
2η,1,
σ
η2,σ
ε 2areidentifiedusingthevariancesEt(
u2i,t)
andthesecond-orderautocovariancesEt(
ui,tui,t+2)
foreachage,year,andcohort.AsinHeathcoteetal.(2010),second-orderautocovariancesareusedbecauseobservationsonlyoccureverytwo-yearsafter1995.Intotal,292momentsidentifythe4 shockprocessparameters,andIusetheoptimalGMMestimator.
Table1displaystheparameterestimates.Thefirst-stageregressioncoefficientsimplymeanlabor efficiencydeclines3% fromage24to30(recallequivalizedwagesareused)andthengrowssteadilyfromage30to64foratotalincreaseof36%. TheestimatedshockprocessishighlypersistentwithparametersremarkablysimilartothoseinStoreslettenetal.(2004). Thisisdespitealargenumberofdifferences,foremostbeingadifferentdependentvariable.
4.2.Calibration
Tousetheestimatedefficiencyprocessparameters,Ispecifythemodelefficiencyprocessanalogouslyto(9)andconvert theannualestimatestothree-yearestimates.Specifically,Itake
ρ
3 asthemodelpersistence,(
1+ρ
2+ρ
4)
σ
2η asthemodel persistentshockinnovationvariance,
σ
2η,1 asthemodelvariance forz1,and
σ
ε 2 asthemodel varianceforthei.i.d.shock.Thisconversiongivesthatthethree-yearaheadforecastmeansandvariancesarethesameinthemodelanddataandthat theinitialvariancesarethesame.Exceptfor
ν
0whichisusedasanormalizationconstant,theage-profileparameterscarryoverdirectly.Forretiredhouseholds,
loge i,t=
ν
0+ν
1h R−1+ν
2h 2R−1+ν
3h 3R−1+z i,R−1+log(
. 5)
(10)wherehR−1=63/10.The log(.5)termgeneratesan exogenous 50%declineinlabor efficiencyandismeant tocapture
re-ducednon-assetincomeinretirement.
Consistentwiththetheory,thepersistentandtransitoryshocksarebothdiscretized.18Thetransitoryshockisdiscretized using3pointsat0and ± 1standarddeviations.The persistentshockisdiscretized using7linearly-spacedpointsonan age-dependentgridthatalways covers3standarddeviations(forretirees,thegridisthesameasforR−1).Thetransition probabilitiesarecomputedusingTauchen(1986)’smethod.
Thelaborgridistakentobearbitrarilyfinebetween0.001and0.999(onecanthinkofthestepsizebetweengridpoints asbeingmachineepsilon).Theassetgridcannotbeasfinesinceincreasingthegridalsoincreasesthesearchspaceforthe planner’soptimalpolicy.Iuse50strictlynegativepointsand250pointsoverall.
Theutilityfunctionischosentobe
(
cθ(
1−n)
1−θ)
1−σ/(
1−σ
)
.Theparameterσ
issetto1+1/θ
sothatconstantrelative riskaversion,1−θ
(
1−σ
)
,equals2foranycalibratedvalueofθ
.Therisk-freepriceq¯issettogivea2%annualrealinterest rate.18 Thegridsusedinthecomputationaresuchthat(ε,z)canalwaysberecovered frome. Thatis,e=f(ε,z) isinvertible,whichisrequiredtobe perfectlyconsistentwiththetheory.Althoughonecanconstructexampleswherefisnotinvertible,thereisalwaysanarbitrarilysmallperturbationoff
Forwelfarecomparisons,Ispecifyanexante welfarefunctionwhere
α
1(
a=0,e)
=πe
forall eandαt
(
a,e)
=0forallothera,e,t(andsotheplannerseekstomaximizewelfareofnewbornhouseholds).Thishasbeenthemostcommonchoice intheliteratureforlife-cyclemodelsfeaturingdefault.19Thiswelfaremeasureaccountsforthewelfareofolderhouseholds becauseV1
(
a=0,e)
implicitlyvaluesutilityatallfuturestatesreachedwithpositiveprobability.Forcomparisonwiththeoptimalpolicyanddeterminingtheremaining parametervalues,Iattempttocapturethe cur-rent U.S. bankruptcy system andthe value of informal default. In the U.S., any householdin good standing can file for bankruptcy,soIsetDt
(
a,e,n)
={
0,1}
foralla,e,n,t.Sinceabankruptcystaysoncreditreportsfor10years,Isetλt
=0.7 (for all t) to match thisduration. Filing costs in the U.S. arecomprised of two main components,official filing fees and attorneycosts.OfficialChapter 7bankruptcyfilingfeesin2016 were$335dollarsbutcanbe waivedfordebtorsearnings lessthan $150belowthe povertylevel (U.S.Courts,2016).Attorney’s fees,whichpresumably areincreasing inlabor effi-ciency,aresubstantial.White(2007)statesthata“typical” debtor’scostoffilingisbetween$1800and$2800(p.192).So,I parameterizeζ
t(a,e,n) toallowforprogressivecostsζ
¯e.Theslopecoefficientζ
¯isthenchosentogiveaveragefilingcosts equalto1% ofaverageearnings.Thisisbased onan$1800 filingcost asa fractionof3 yearsofearningsat$60,000.The psychiccostsκ
(e)areparameterizedasmax{
0,κ
0+κ
1zi,t+κ
2ε
i,t}
.Informaldefaultismodeledasautarkywithanadditionalpsychiccost
κ
O≥0inthefirstperiod,whichmakesVO t(
a,e)
=VA
t
(
a,e)
−κ
O.20 Thecostκ
O ismeanttocaptureallcostsassociatedwithinformaldefaultsuch asphonecallsfrom credi-torsandwagegarnishments(withthemaintainedassumptionthatallcollectioneffortshaveazeronetrecoveryrate).For approximatingthecurrentU.S.system,Itreatκ
Oasaparameterandcalibrateit.LaterinthissectionIwilltreatκ
Oasthe planner’spolicyinstrumentγ
(recallγ
influencestheoutsideoptionvalue)andassumetheplannercanmakeκ
Oarbitrarily large.Inthenextsection,Iwillassumetheplannercanonlychooseκ
O=0.The8parameters
(
β
,θ
,ν
0,κ
0,κ
1,κ
2,κ
O,ζ
)
are usedtomatch8momentsfromthedata.The discountfactorβ
ispri-marilyusedtomatchawealth-incomeratioof1basedonanannualratioof3.TheCobb–Douglasutilityweight
θ
isused tomatchthefractionofhours spentworking.InthePSIDsamplewithagerestrictionsbutnorestrictiononhoursworked, thefractionofpotential worktimespent workingis27.6%.(Thisestimateassumes16hofworktimeadaywith365work daysavailable peradult.)The earningsprocess parameterν
0 sets averageearnings to1,anormalization. Thepsychiccostparameters
κ
0,κ
1,κ
2areusedtomatchadebt-incomeratioof0.028,afilingrateof1.20%,andanannualizedinterestrateof12.7%.ThefirstnumberisatriennialconversionoftheannualnumberinLivshitsetal.(2007),thefilingrateisbasedon Chapter7and13personal bankruptcyfilingsrelative totheworkingagepopulationin2015convertedtoa triennialrate, andthelastisfromGordon(2015).Theproportionalfilingcostparameter
ζ
isusedtomatchafilingcost-earningsratioof 0.01.Thinkingoftheoutsideoptionasanabsorbingstatewithdebtsinpermanentcollection,thepsychiccostofinformal defaultκ
Oisusedtotargetthepercentofconsumerswithathird-partycollection.Inthepastdecadethishasvariedfrom 12to15%(FRBNY,2017),andIuse13%asatarget.ThecalibratedparametersandmomentsaregiveninTable2.Themodeldeliverseverytargetedmomentwithmixedperformancefortheuntargetedmoments.Thepopulationindebt isintherangeof6.7%(Chatterjeeetal.,2007)and17.6%(Wolff,2010),theformermeasuringstrictlynegativedebtpositions andthelatterweaklynegative.Theannualizedcharge-off rateisabouttwicewhatitshouldbe,buttheimpliedmodelrateis closelylinkedtotheinterestratebecausetherearenotransactioncosts.21Asistypicallythecaseforanormallydistributed efficiencyprocess,themodelunder-predictsearningsandwealthinequality.
Themodel’simpliedpsychiccostsareincreasinginbothpersistentandtransitoryearningswithamedianvalueof1.06. Thismedianvalueisverylarge,around16%intermsofconsumptionequivalentvariationforanewborn,andconsequently householdswithabove-medianearningsdefaultveryinfrequently.However,thepsychiccostsquicklygotozerofor house-holdswithnegativeshocks.e.g.,foratransitoryshockone-standarddeviationbelowitsmean,
ε
it=−0.25,thepsychiccost iszeroifzi,t iszero.Fig.1 plotslife-cycleprofiles forconsumption,earnings, assetholdings,anddefaultrates(bothbankruptcy filingrates andoutsideoptiontake-uprates).Inthedata,bankruptciesaremostfrequentamong30–47yearolds(Livshitsetal.,2007, Figure1,p.404).Themodelcapturesthisbutistooextremewithessentiallynoonefilingforbankruptcyafterage45.Older householdsprefertheoutsideoptionbecausetheyhavelittleneedtoborrowinretirement,whichmakesgoing toautarky (withtheadditional
κ
Ocost)relativelylesscostly.4.3. Baselinecases
Before analyzing thefull optimal policy,it is usefulto considersome baseline cases.The first baseline is the current U.S. system (referred to as US). The second is a zero borrowinglimit (ZBL) economy where qt
(
a,e)
=0 for all a<0, e,t, whichprovides a lower bound onutility.A thirdbaseline case isa naturalborrowinglimit (NBL)economy, which has
Dt
(
a,e,n)
={
0}
for all states.The last baseline must,by Corollary 1, improveon the NBL economy. Thispolicy specifies19Forinstance,Livshitsetal.(2007),Athreyaetal.(2009b)andGordon(2015)allusethis.Whiletestingotherwelfarefunctionsistrivial,thishasnot beendoneforbrevity.
20Tobeprecise,onceahouseholdchoosestheoutsideoption,theirpoliciesareasifinautarky.Thatis,theirpoliciesaretheoptimalpolicies correspond-ingto(2)witha=0inthefirstperiodandwhateverisimpliedbytheautarkypoliciesandshocksthereafter.Consequently,VO
t(a,e) =Xt(0,e) −κ(e) −κO
fora<0.Bydefinition,VA
t(a,e) :=Xt(0,e) −κ(e) fora<0,soVtO(a,e) =VtA(a,e) −κO.
Table2
Calibration.
Statistic Target Model Param. Value
Independentlydetermined
Annualrisk-freerealinterestrate 2% 2% q¯ 0.942
Badcreditrecordduration(years) 10 10 λ 0.7
Relativeriskaversion 2 2 σ 1+1/θ
Jointlydetermined
Pct.ofhouseholdsfiling 1.20 1.28 κ0 1.06
Pct.ofhouseholdseverchoosingoutsideoption 13.00 13.10 κO 0.008
Debt-earningsratio× 100 2.80 2.69 κ1 1.23
Annualizedinterestrate 0.127 0.132 κ2 5.72
Wealth-incomeratio 1.00 1.01 β1/3 0.945
Filingcost-earningsratio 0.010 0.010 ζ¯ 0.008
Laborsupply 0.28 0.27 θ 0.36
Earnings(normalization) 1.00 1.01 ν 2.03
Untargetedmoments
Populationindebt∗ 6.7%–17.6% 11.6%
Annualizedcharge-off rate 0.05 0.10
Debt-incomeoffilers 0.54 0.90
Filerswithbelow-medianincome 0.69 1.00
Earningsgini 0.61 0.50
Wealthgini 0.80 0.72
Mean-medianearnings 1.57 1.51
Mean-medianwealth 4.03 2.46
Meanefficiency(normalization) – 2.92
Note:Modelincomeismeasuredasen+(1/q¯−1) aand“indebt” isa<0.
Table3
Welfareandallocationsfromdifferingdefaultpolicies.
Statistic ZBL US NBL D{} D∗ Simple Naive D∗
asym
WelfaregainrelativetoUS −1.18 0.00 5.42 7.43 11.6 10.6 3.47 5.54
Filingrate(%) 0.00 1.28 0.00 1.48 2.91 2.12 1.02 1.26
Defaultrate(%) 0.00 2.33 0.00 1.48 2.91 2.12 1.02 1.26
Totaldebt 0.00 0.03 0.12 0.29 0.46 0.60 0.07 0.13
Pop.indebt(%) 0.00 11.6 30.0 30.6 40.1 39.6 24.0 29.6
Interestrate(%) – 13.2 2.00 6.15 6.19 4.64 4.04 3.86
Charge-off rate (%) – 10.4 0.00 8.22 4.40 3.55 2.22 2.60
Totalassets 1.17 1.03 0.93 0.80 0.50 0.30 1.02 0.92
Totalconsumption 1.07 1.00 1.07 1.06 1.06 1.05 1.07 1.07
Totalearnings 1.00 1.01 1.01 1.02 1.03 1.04 1.01 1.01
Misreporting(%) – 0.00 – 0.00 0.00 0.00 23.6 25.8
Totaloutsideoption(%) 0.00 13.1 0.00 0.00 0.00 0.00 0.00 0.00
Note:Interestandcharge-off rateshavebeenannualized;Misreportingistherateconditionalonfiling; Totalassetsaremeasuredasa(1−max{d,o}) dμ(capitalingeneralequilibrium).
Dt
(
a,e,n)
={
0}
forallstateshavingVtR(
a,e)
<VtO(
a,e)
orVtR(
a,e)
undefined.IrefertothisastheD{}economy.Forallthe policiesexceptUS,Itakeκ
Oarbitrarilynegativetofocusonwhatoptimalbankruptcypolicycanachieveifinformaldefault canbemadeverycostly(κ
O=0willbetakenupinSection5).TheresultsforZBL,NBL,US,andD{}aresummarizedinTable3.Thereportedwelfaregainistheconsumptionequivalent
welfaremeasurerelativetoUS.ZBLisworsethanUSwithawelfarelossof1.2%.NBLontheotherhanddoesmuchbetter witha welfaregain of5.4%.ComparingtheamountsofdebtinUSandNBL,debtisroughly 4timeslargerinNBL.These findingsagreewithalargeliterature thathasfoundtheNBLdoesmuchbetterthanmodeleconomiescalibratedtomatch U.S.datamomentsbecauseimprovedcreditallowshouseholdstoself-insure well.Fig.1showsNBLincreasesconsumption ofyounghouseholdsrelativetoUS,reducingsavingsearlyinlife.Front-loadingconsumptionimproveswelfaresince
β
/q¯is significantlylessthan1.D{} generatesa7.4%welfaregainrelativetoUS,2percentagepointslargerthanNBL’sgain.WhileCorollary1showsD{}
mustweaklyoutperformNBL,quantitativelythereisasizabledifference.ThisisdespiteD{}andNBLdifferingonlyinstates
wherehouseholdscannotrepay,inwhichcaseD{} providesafreshstartandNBLdoesnot.WhileimplementingNBLwould
beverycostly(probablyinvolvingareturntodebtors’prisons),implementingD{}wouldbemuchlesscostly:Courtswould
30 40 50 60 70 80 0.8
0.9 1 1.1 1.2 1.3 1.4
Consumption
30 40 50 60 70 80
0.4 0.6 0.8 1 1.2 1.4 1.6
Earnings
D*
NBL
US
30 40 50 60 70 80
Age
0 1 2
3
Assets
30 40 50 60 70 80
Age
0 0.02 0.04 0.06 0.08
Default Rates
Bankruptcy
Outside Option
Fig.1. Life-cycleprofilesforD∗,NBL,andUS.
4.4. Theoptimalbankruptcyrule
Thefulloptimalpolicy,labeledD∗,isnowconsidered.Itiscomputedusingageneticalgorithmandmultigridonasuper computerwiththehouseholdproblemsolvedsixmilliontimes.InterestedreadersmayconsultAppendixBformoredetails. AscanbeseeninTable3,D∗generatesa11.6%welfaregainrelativetoUS,morethandoublingNBL’s5.4%gain.Tosee whythewelfaregain isso large,firstnote thatrelative toUS,D∗ generates15timesmore debtand,despitethis, similar defaultrateswith50% lowerinterest rates.Thisdebtisevidenceofimprovedconsumptionsmoothingthat isalsoevident inthelife-cycleprofilesinFig.1.UnderD∗,anaveragehouseholdaccumulatesdebtequaltoroughlyhalfofmeanearnings by age40.It isnot until themid-40swhere deleveragingoccursandmeanassetsgrow inpreparationforretirement.In contrast,USandNBL havepositiveaverage assetpositionsthroughoutthelife-cycle.D∗’s largerdebtamounts inmid-life increase labor through a negative wealth effecton leisure, which results in households workingmore when their labor efficiencyishighest.Asaresult,averageearningsare2%largerinD∗thaninUS(ascanbeseeninTable3).
Theoptimalpolicyimprovesconsumptionsmoothingbyallowingbankruptcyonlyforthosewhobenefitthemostfrom it. Thiscan be seen inFig. 2, whichplots the optimalpolicy forselect ages.A blackdot means that the state is visited in equilibriumwithprobability greater than 10−5.A blueplus sign meansthat the householdfilesfor bankruptcyifthe
plannerletsthem,i.e.,dt
(
a,e)
=maxDt(
a,e,n)
.AredcirclemeansDt(
a,e,n)
={
0,1}
,andsothehouseholddefaults.These parts ofthepolicy arethe mostmeaningfulbecausechanging thepolicy from{0,1}to{0}hasa directeffecton default decisions andthe planner’sobjectivefunction (byvirtueof exantewelfare andthe probability beinggreaterthan 10−5).Thehorizontalaxisisdebt(recallaverageearningsareroughly1),andtheverticalaxisgivesthestandarddeviationsfrom thepersistentshockmean.Thetopandbottompanelspresentthepolicyforthemedianandworsttransitoryshockvalues, respectively.
The optimalpolicytends to allowbankruptcywhen, conditionalon alevel ofdebt,householdsreceivethe worst per-sistent shock occurringwithsome non-negligible probability. Inthis sense, theplanner onlyallows default forthe most unlucky households. Restricting defaultto only a small fraction of households is important because default rates effec-tively act as a borrowing tax: Borrowing interest rates relative to risk-free rates are 1/
(
1−Ee|e,tdt+1(
a,e))
or roughlyEe|e,tdt+1
(
a,e)
forsmalldefaultrates;hence,ax%defaultratetranslates(roughly)intoaborrowingtaxofx%.Theoptimalpolicymitigatesthisdistortionbyrestrictingdefaulttothosewhobenefitthemostfromit.
0 0.5 1 1.5 2 2.5 -3
-2 -1 0 1 2 3
Stdev from persistent mean
Median transitory shock, Age 30
Pr>.00001
& d=maxD
& d=1
0 1 2 3 4 5
-3 -2 -1 0 1 2
3
Median transitory shock, Age 51
0 0.5 1 1.5 2 2.5
Debt
-3 -2 -1 0 1 2 3
Stdev from persistent mean
Worst transitory shock, Age 30
0 1 2 3 4 5
Debt
-3 -2 -1 0 1 2
3
Worst transitory shock, Age 51
Fig.2. Theoptimalpolicybyage.
peoplewish to file inresponse tothe negativetransitory shock, theplannergenerallydoesnot let them(i.e., anegative transitoryshockcreatesmoreblueplussignsbutnotmanymoreredcircles).
Theoptimalpolicyrespondsmoretopersistentshocksthantransitoryshocksbecausethelatterareeasilyinsuredusing creditwhiletheformerarenot. Becausetransitoryshockshavenoimpactonfutureearnings, anegativeshockhittingan aget householdhasno impact onqt(a,e). Hence, householdscan readilyborrow to smooth out thissmallreduction in lifetimeincome.Incontrast,persistentshocksare muchhardertoself-insure via credit.Notonlydo theyreduce lifetime incomebyasubstantialamount,theyalsoreduceqt(a,e),whichmakesborrowingcostlypreciselywhenhouseholdswant toborrow. So,the planneris more likelyto offer bankruptcyin response to anegative persistentshock thana negative transitoryone.
Livshitsetal.(2007),Athreyaetal.(2009a),andothershaveshownthathigh-bankruptcy-costregimesaremore prefer-ablewhen shocks arelesspersistent andconverselyforlow-cost regimes. Theoptimal policy—by treating persistentand transitoryshocksdifferently—canhavethebestofbothworlds,requiringhouseholdstoself-insureagainsttransitoryshocks butallowingbankruptcyforinsuranceagainstpersistentones.
5. Constraintsontheoptimalpolicy
Theoptimalbankruptcypolicy vastlyimproveswelfare.However, the11.6%welfaregain isanupperbound becauseof three constraints on optimal policy.The first constraint is that the policy should be simple enough forhouseholds and creditors to understand. The second constraintis asymmetric informationwith moral hazard:By tying debtforgiveness toparticularefficiencylevels,theoptimalpolicy underasymmetricinformationincentivizeshouseholdstomisreporttheir efficiencystatus.Thethirdconstraintislimitedcommitmentinducedbyanattractiveoutsideoption.Thissectionexplores howmucheachoftheseconstraintsaffectstheoptimalpolicy.
5.1. Simpleimplementation
Fig.3. AveragemarginaleffectonPr(maxD|).
Ofcourse,theparameterizationshould beabletocapturemuch oftheoptimalpolicy’svariationintherelevantregion ofthestate space, whichistheset
=
{
(
a,e,t)
|
VDt
(
a,e)
>VtR(
a,e)
orVtR(
a,e)
infeasible}
.Foranystate in,households choosedt
(
a,e)
=maxDt(
a,e,n)
andsochangingDt(a,e,n)from{0,1}to{0}orviceversaleadstoadirecteffectondefault decisions.Sucha changewillalsohaveadirecteffectonplannerwelfaretotheextentthestate isvisitedinequilibrium. Aftersomeexperimentation,thelogitregressionP r
(
maxD i,t=1)
=1/(
1+exp(
−δ
i,t))
,δ
i,t = b 0+b 11[age i,t≥40]+b 2log(
−a i,t)
+b 3z ˜i,t+b 4