Bank Capital Regulation and Endogenous Shadow
Banking Crises
Johannes Poeschl1 Xue Zhang2
1Danmarks Nationalbank
2KBC
Federal Reserve Day Ahead Conference
January 2019
Any views expressed in this presentation are our own and do not reflect those ofDanmarks Nationalbank or KBC.
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Shadow banking sector: large and crisis-prone
Total financial assets of retail and shadow banks. Constructed as in Adrianand Shin (2011). Source: Financial Accounts of the U.S.
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New challenges for bank regulators
Systemic shadow banking crises
I How costly are shadow banking crises?I Can capital requirements on traditional (retail) banks mitigate
shadow banking crises?
Interlinkages between retail and shadow banks
I Do spillover effects mitigate the effectiveness of bank capitalrequirements?
This paper: Quantitative model addressing these new challenges
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The main findings in a nutshell
1 Shadow banking crises are rare, but costly
I Eliminating banking crises: welfare gain of 1.7 percentI 80 percent of the welfare gain: elimination of bank run fears
2 Higher retail bank capital requirements, fewer shadow banking
crises
I Traditional (retail) banks: Smaller fire sale discounts
3 Novel spillover effect of retail bank capital requirements
I Reduction of bank run fears relaxes shadow bank leverageconstraint
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(Non-exhaustive) literature reviewShadow Banks:Gennaioli, Shleifer, and Vishny (2013), Plantin (2014), Gertler,Kiyotaki, and Prestipino (2016), Huang (2018), Moreira and Savov(2017), Begenau and Landvoigt (2017), Meeks, Nelson, andAlessandri (2017), Farhi and Tirole (2017), Ferrante (2018) . . .
Banking crises in macroeconomic models:Gertler and Kiyotaki (2013), Garcia-Macia and Villacorta (2016),Gertler, Kiyotaki, and Prestipino (2017) Boissay, Collard, and Smets(2016), Paul (2018) . . .
This paperEndogenous & anticipated shadow banking crises
+ endogenous wholesale funding market
⇒ New spillover effect of retail bank capital requirements
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Agenda
1 Introduction
2 Model
3 Equilibrium
4 Eliminating Shadow Banking Crises
5 Effects of Retail Bank Capital Requirements
6 Conclusion
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AgentsModel follows Gertler et al. (2016)
Time t = 0, . . . ,∞Banks
I Retail banks R, shadow banks SI issue deposits, lend on retail funding market, borrow & lend on
wholesale funding marketI differ by exit probability σR < σS and investment inefficiencyηR > ηS = 0
Households HI Lend on retail funding market, save in depositsI Own all banks and firmsI Inefficient investors: ηH ηR
FirmsI Consumption goods producersI Capital goods producers
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Banks’ objective function
Banks of type J maximize payouts to households
E0
∞∑
t=0
Λ0,t (1− σJ)t−1σJ︸ ︷︷ ︸Probability ofexit in period t
nJt
,
with net worth nJt , stochastic discount factor Λ0,t , exit probability σJ
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Banks’ balance sheet and net worth
Balance sheet constraint
dJt+1 + nJ
t︸ ︷︷ ︸Liabilities + Equity
= bJt+1 + (Qt + f J
t )aJt+1︸ ︷︷ ︸
Assets
with deposits dJt+1, wholesale loans bJ
t+1, retail loans aJt+1, capital
price Qt , retail loan servicing fee f Jt (increasing in ηJ )
Net worth
nJt = RA
t aJt + RB
t bJt − RD
t dJt
with returns on retail loans RAt , on wholesale loans RB
t , and
deposits RDt
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Financial friction and bank capital structure
Banks can divertI a fraction ψ of deposit or equity financed retail loansI a fraction ψγ of wholesale (interbank) loansI a fraction ψω of wholesale financed retail loans
Incentive constraint, e.g. for wholesale lenders (bJt+1 > 0):
ψ[(Qt + f J
t )aJt+1 + γbJ
t+1
]≤ V J
t = ΩJt nJ
t ,
with continuation value V Jt , unit continuation value ΩJ
t
Implies an endogenous upper bound on bank leverage
ψφJt ≤ ΩJ
t
Details - retail banks Details - shadow banks
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Bank Default
We consider only default on wholesale loans. Deposits are
non-defaultable.
Insolvent banks liquidate their assets at discount ξ < 1
Recovery value of wholesale creditors:
xt = ξRA
t aJt
RBt bJ
t
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Bank Regulation
Regulator can impose a minimum capital requirement, which
corresponds to an upper bound on bank leverage φJt :
φJt ≤ φJ
t
φJt is chosen according to a modified incentive constraint, e.g.
for wholesale lenders
ψφJt (1 + τ J
t ) ≤ ΩJt
Interpretation: Social cost of bank leverage is by a factor of τ Jt
higher than private cost of leverage (e.g. due to externalities)
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Rest of the Model
HouseholdsI ConsumeI Supply labor inelasticallyI Invest in deposits and retail loans Details
Final goods producersI Use retail loans to purchase capitalI Transform capital and labor into consumption goodsI Cobb-Douglas technologyI Productivity shock Details
Capital goods producersI Transform consumption goods into investment goodsI Quadratic capital adjustment cost Details
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Agenda
1 Introduction
2 Model
3 Equilibrium
4 Eliminating Shadow Banking Crises
5 Effects of Retail Bank Capital Requirements
6 Conclusion
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Equilibrium flow of funds - model overview
Flow of funds in equilibrium.
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Self-fulfilling and systemic bank runsSystemic shadow bank default reduces the return on retail loans
(capital) from RAt to RA∗
t
Net worth of incumbent shadow banks NS,It increases in the return
on retail loans: ∂NS,It /∂RA
t > 0
Two equilibriaHigh return on retail loans, solvent shadow banks (normalequilibrium)
Low return on retail loans, insolvent shadow banks (shadow bankrun equilibrium)
Run equilibrium selected if sunspot Ξt ∈ 0,1 is 1, with
Pr(Ξt = 1) = η(1− x∗t )
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A situation with two equilibria
Investment Quantity It
Cap
ital P
rice
Qt
Capital Market Equilibrium
Investment Demand Investment Supply Bank Run Cutoff
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Existence condition for two equilibria
Existence condition for the shadow bank run equilibrium:
x∗t ≤ 1 ⇐⇒ ξRA∗t AS
t ≤ RBt Bt .
with fire sale return on retail loans RA∗t , return on wholesale loans
RBt , liquidation loss ξ
Can be rewritten as
ξRA∗
t /Qt−1
RBt︸ ︷︷ ︸
Shadow bankfire sale
profit margin
φSt−1
φSt−1 − 1︸ ︷︷ ︸
Shadow bankleverage
≤ 1
This condition is not internalized by banks
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Agenda
1 Introduction
2 Model
3 Equilibrium
4 Eliminating Shadow Banking Crises
5 Effects of Retail Bank Capital Requirements
6 Conclusion
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CalibrationRole Name Value Target or Source
(a) Technology and Preferences
Capital share in production α 0.36 Standard valueDepreciation Rate δ 0.025 Standard valueRisk Aversion σ 2 Standard valueHousehold discount factor β 0.9902 RD − 1 = 4% p.a.Capital adjustment cost θ 10 ∂ ln(Qt )
∂ ln(It )
∣∣∣ = 0.25
(b) Financial Sector
Banks’ initial equity υ 0.001 Planning horizons of banksDiversion benefit of wholesale lending γ 0.6676 RB − RD = 0.8% p.a.Household capital holding cost ηH 0.0286 RK − RD = 2.4% p.a.Retail bank capital holding cost ηR 0.0071 RK ,R − RD = 1.2% p.a.Retail bank exit rate σR 0.0521 K R/K = 0.4Shadow bank exit rate σS 0.1273 K S/K = 0.4Asset diversion share ψ 0.2154 φR = 10Diversion benefit of wholesale funding ω 0.5130 φS = 20
(c) Bank Runs and Stochastic Processes
Autocorrelation, productivity ρZ 0.9 ρ(Yt ,Yt−1) = 0.9Standard Deviation, productivity shock σZ 0.01 σ(Yt ) = 0.03Loss in Default ξ 0.9 Retail bank net worth in run -30 %Sunspot probability shifter η 0.25 Crisis freq. of ≈ 0.75% per quarterReentry probability after bank run π 12/13 Runs last 3.25 yrs on avg
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Shadow bank run risk reduces shadow bank leverage
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1
10
15
20
25
30
35
40
45
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Eliminating shadow banking crises
With Runs No Runs Only Exp.
Macroeconomic Aggregates
Mean, Output (Y ) 1.088 1.114 1.093St. Dev., Output (Y ) 3.181 3.275 3.192
Financial Sector
Mean, Retail Bank Leverage (φR) 10.291 10.019 10.239Mean, Shadow Bank Leverage (φS) 13.444 19.995 13.244
Bank Runs
Runs per 100 Years 3.100 0.000 0.000Recovery Rate (xt |Runt ) 78.214 - -
Welfare 0.850 0.865 0.853
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Agenda
1 Introduction
2 Model
3 Equilibrium
4 Eliminating Shadow Banking Crises
5 Effects of Retail Bank Capital Requirements
6 Conclusion
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Retail CR push fire sale prices up
0.2 0.4 0.6 0.8 1
2.8
3
3.2
3.4
3.6
0.2 0.4 0.6 0.8 1
1.014
1.015
1.016
1.017
1.018
1.019
1.02
0.2 0.4 0.6 0.8 1
0
10
20
30
40
50
0.2 0.4 0.6 0.8 1
12
12.5
13
13.5
14
14.5
15
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Effectiveness of retail bank capital requirements
With Runs No Runs
Baseline τR = 0.5 Baseline τR = 0.5
Macroeconomic Aggregates
Mean, Output (Y ) 1.088 1.082 1.114 1.101St. Dev., Output (Y ) 3.185 3.204 3.279 3.302
Financial Sector
Mean, Retail Bank Leverage (φR) 10.291 8.057 10.019 7.571Mean, Shadow Bank Leverage (φS) 13.444 14.847 19.993 20.820
Bank Runs
Runs per 100 Years 3.096 2.899 0.000 0.000Recovery Rate (xt |Runt ) 78.212 78.725 - -
Welfare 0.850 0.848 0.865 0.860
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Correcting for the spillover increases the effectiveness
of retail CR
0.05 0.1 0.15 0.2 0.25 0.3
2.5
3
3.5
0.05 0.1 0.15 0.2 0.25 0.3
1.014
1.015
1.016
1.017
1.018
1.019
1.02
0.05 0.1 0.15 0.2 0.25 0.3
0
10
20
30
40
50
0.05 0.1 0.15 0.2 0.25 0.3
12
12.5
13
13.5
14
14.5
15
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Correcting for the spillover effect
With Runs
Baseline Regulation RegulationW Spillover W/O Spillover
Macroeconomic Aggregates
Mean, Output (Y ) 1.088 1.082 1.079St. Dev., Output (Y ) 3.184 3.202 3.179
Financial Sector
Mean, Retail Bank Leverage (φR) 10.291 8.057 8.033Mean, Shadow Bank Leverage (φS) 13.444 14.847 13.436
Bank Runs
Runs per 100 Years 3.105 2.909 2.630Recovery Rate (xt |Runt ) 78.213 78.728 79.427
Welfare 0.850 0.848 0.846
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Conclusion
Quantitative nonlinear DSGE model to evaluate effectivness ofretail bank capital requirements to reduce shadow banking crises:
I Endogenous wholesale lending marketI Endogenous and anticipated shadow bank runs
Main findings:I Shadow bank runs have a large welfare cost, mostly through
anticipation effectsI Retail bank capital requirements can reduce the frequency and
severity of shadow bank runsI Retail bank CR create a spillover due to a relaxed shadow bank
leverage constraint, which mitigates their effectiveness substantially
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Appendix
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Households
maxkH
t+1,dHt+1,c
Ht
E0
[ ∞∑t=0
βtU(cHt )
]
s.t.
cHt = nH
t −QtkHt+1−dH
t+1−ηH
2
(kH
t+1
Kt
)2
Kt +
(f Rt −
ηR
2kR
t+1
Kt
)kR
t+1
nHt =
[rKt + (1− δ)Qt
]kH
t + (1 + rDt )dH
t + Wt + ΠQt
Back
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Retail Banks
Define the value function of a banker as: V Rt = σnR,C
t + (1 − σ)V R,Ct
The value function of a continuing banker is given by:
V R,Ct = max
kRt+1,dt+1,bt+1
βEt
[V R
t+1
]s.t.
nR,Ct + dt+1 = (Qt + f R
t )kRt+1 + bt+1 (Balance Sheet Constraint)
ψ((Qt + f Rt )kR
t+1 + γbt+1) ≤ βEt
[V R
t+1
](Incentive Constraint)
nR,Ct ≥ Γ((Qt + f R
t )kRt+1 + γbt+1) (Bank Capital Requirement)
where net worth of continuing bank isnR,C
t = (rKt + (1 − δ)Qt )kR
t + RBt+1bt − RD
t dt .
Net worth of all banks: NBt = (1 − σ)nR,C
t + σωKt
Back
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Shadow Banks
Define the value function of a banker as: V St = σnS,C
t + (1 − σ)V S,Ct
The value function of a continuing banker is given by:
V S,Ct = max
kSt+1,bt+1
βEt
[V S
t+1
]s.t.
nS,Ct + bt+1 = QtkS
t+1 (Balance Sheet Constraint)
ψ(ωbt+1 + nS,Ct ) ≤ βEt
[V S
t+1
](Incentive Constraint)
where net worth of continuing bank isnS,C
t = (rKt + (1 − δ)Qt )kR
t + RBt+1bt − RD
t dt .
Net worth of all banks: NBt = (1 − σ)nS,C
t + σωKt
Back
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Production
Final Goods Producers:
maxKt ,Lt
ZtKα
t L1−αt −WtLt − rK
t Kt
Capital Goods Producers:
maxit
Qt it − it −
θ
2
(itKt− δ)2
Kt
FOC:
Qt = 1 + θ
(itKt− δ)
Back
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Adrian, T. and H. S. Shin (2011). Chapter 12 - Financial Intermediariesand Monetary Economics. In Handbook of Monetary Economics,Volume 3, Chapter 12, pp. 601–650. Elsevier Ltd.
Begenau, J. and T. Landvoigt (2017). Financial Regulation in aQuantitative Model of the Modern Banking System. Working Paper,Harvard , 1–53.
Boissay, F., F. Collard, and F. Smets (2016). Booms and BankingCrises. Journal of Political Economy 124(2), 489–538.
Farhi, E. and J. Tirole (2017). Shadow Banking and the Four Pillars ofTraditional Financial Intermediation. Unpublished Manuscript .
Ferrante, F. (2018). A Model of Endogenous Loan Quality and theCollapse of the Shadow Banking System. American EconomicJournal: Macroeconomics 10(4), 152–201.
Garcia-Macia, D. and A. Villacorta (2016). Macroprudential Policy withLiquidity Panics. Technical report.
Gennaioli, N., A. Shleifer, and R. W. Vishny (2013, aug). A Model ofShadow Banking. The Journal of Finance 68(4), 1331–1363.
Gertler, M. and N. Kiyotaki (2013). Banking, Liquidity and Bank Runsin an Infinite-Horizon Economy. Working Paper .
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Gertler, M., N. Kiyotaki, and A. Prestipino (2016). Wholesale Bankingand Bank Runs in Macroeconomic Modelling of Financial Crises (1ed.), Volume No. 21892. Elsevier B.V.
Gertler, M., N. Kiyotaki, and A. Prestipino (2017). A MacroeconomicModel with Financial Panics. Unpublished Manuscript .
Huang, J. (2018). Banking and Shadow Banking. Journal of EconomicTheory 178, 124–152.
Meeks, R., B. Nelson, and P. Alessandri (2017). Shadow Banks andMacroeconomic Instability. Journal of Money, Credit andBanking 49(7), 1483–1516.
Moreira, A. and A. Savov (2017). The Macroeconomics of ShadowBanking. The Journal of Finance 72(6), 2381–2432.
Paul, P. (2018). A Macroeconomic Model with Occasional FinancialCrises. Federal Reserve Bank of San Francisco Working Paper .
Plantin, G. (2014). Shadow Banking and Bank Capital Regulation.Review of Financial Studies.
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