systemic real and financial risks: measurement, forecasting, and stress testing gianni de nicolò...
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Systemic Real and Systemic Real and Financial Risks: Financial Risks: Measurement, Measurement, Forecasting, Forecasting,
and Stress Testing and Stress Testing Gianni De NicolòGianni De Nicolò
International Monetary Fund and CESifoInternational Monetary Fund and CESifo
Marcella LucchettaMarcella LucchettaUniversity of VeniceUniversity of Venice
The views expressed in this paper are those of the authors and do The views expressed in this paper are those of the authors and do not necessarily represent those of the IMF.not necessarily represent those of the IMF.
Motivation Motivation
Available monitoring technologies failed to Available monitoring technologies failed to provide early warnings on the crisis in 2007-provide early warnings on the crisis in 2007-2008. 2008.
Building on De NicolBuilding on De Nicolò and Lucchetta (2010), and Lucchetta (2010), we develop a model that can be useful for we develop a model that can be useful for
positive analysis, positive analysis, andand as a systemic risk monitoring system.as a systemic risk monitoring system.
Limitations of current Limitations of current modelingmodeling
DSGE models DSGE models 1.1. Incorporation of interactions between financial and Incorporation of interactions between financial and
real sectors still in its infancy real sectors still in its infancy 2.2. Forecasting performance not yet firmly established. Forecasting performance not yet firmly established.
Stress testing proceduresStress testing procedures1.1. ““shocked” variables typically shocked” variables typically endogenous (shock to endogenous (shock to
the “cause” or the “symptom”?)the “cause” or the “symptom”?)2.2. difficult to assess the quantitative results.difficult to assess the quantitative results.
Our contributionOur contribution Our model complements DSGE modeling by Our model complements DSGE modeling by
exploiting: exploiting:
the the forecasting power of a Dynamic Factor Model forecasting power of a Dynamic Factor Model (DFM) (DFM) with many predictorswith many predictors
structural identification structural identification based on explicit based on explicit theoretical constructs (such as DSGE models)theoretical constructs (such as DSGE models)
Flexibility (Flexibility (applicable to multiple countries/sector applicable to multiple countries/sector datasets, and different data frequencies). datasets, and different data frequencies).
Output of the ModelOutput of the Model
a)a) density forecasts density forecasts of indicators ofof indicators of systemic real risk and systemic systemic real risk and systemic financial risk;financial risk;
b)b) reduced-form stress tests, reduced-form stress tests, as as historical simulations;historical simulations;
c)c) structural stress-tests, structural stress-tests, as as impulse responses of systemic risk impulse responses of systemic risk indicators to structural shocks indicators to structural shocks identified by standard identified by standard macroeconomic and banking theory. macroeconomic and banking theory.
Systemic Real Risk Systemic Real Risk
Systemic Real Risk is measured by GDP-Expected Shortfall (GDPES), given by the expected loss in GDP growth conditional on a given level of GDP-at-Risk (GDPaR)
GDPaR is the worst predicted realization of quarterly growth in real GDP at a given (low) probability
Systemic Financial RiskSystemic Financial Risk A financial health indicator (FS) : return of a
portfolio of financial firms less the return of the market
Systemic Financial Risk is measured by FS-Expected Shortfall (FSES) , given by the expected loss in FS conditional on a given level of FS-at-Risk (FSaR)
FSaR is the worst predicted realization of the FS indicator at a given (low) probability level
The statistical models The statistical models GDP growth and FS are modeled through GDP growth and FS are modeled through
a version of a a version of a factor-augmented VAR factor-augmented VAR (FAVAR)(FAVAR) model (e.g. Stock and Watson, model (e.g. Stock and Watson, 2002 and 2005)2002 and 2005)
Density forecasts of GDPG and FS obtained estimating a set of quantile auto-regressions
Systemic Risk Indicators constructed using density forecasts
STRESS TESTING = STRESS TESTING = Measurement of Measurement of impact impact and and persistencepersistence
of configurations of of configurations of unexpected unexpected (structural) shocks (structural) shocks
on systemic risk indicatorson systemic risk indicators
Reduced-form stress tests: based on shocks recovered from a statistical model of the
quantiles (distribution) of GDP growth and FS
Structural stress tests: based on shocks derived from theoretical models IdentificationIdentification ofof structural shocks structural shocks accomplished with accomplished with
theory-based sign restrictions (Canova and De Nicolò, JME theory-based sign restrictions (Canova and De Nicolò, JME 2002)2002)
ImplementationImplementation
We use macroeconomic and financial series for the G-7 economies for the period 1980:Q1-2010:Q1
For each country, the vector of quarterly series includes about 95 series classified into
1. equity markets data2. credit conditions3. indicators of real activity
Main Results Main Results
1.1. Significant forecasting power for Significant forecasting power for tail risk tail risk realizations of real activity realizations of real activity and financial healthand financial health
2.2. Both reduced-form and structural Both reduced-form and structural stress tests provide early warnings stress tests provide early warnings of real and financial vulnerabilitiesof real and financial vulnerabilities
3.3. In all countriesIn all countries:: aggregate demand shocks drive the aggregate demand shocks drive the
real cyclereal cycle bank credit demand shocks drive the bank credit demand shocks drive the
bank lending cycle bank lending cycle real drives financialreal drives financial
Plan of the presentationPlan of the presentation
The ModelThe Model Estimation and Forecasting (details)Estimation and Forecasting (details) Forecast EvaluationForecast Evaluation Reduced-Form Stress TestsReduced-Form Stress Tests Structural Stress TestsStructural Stress Tests Modeling DevelopmentsModeling Developments
The Dynamic Factor Model The Dynamic Factor Model (DFM)(DFM)
(static form)(static form)
11 1( )R
t t R t tGDPG F L GDPG u
21 1( )F
t t F t tFS F L FS u
X it
iF
t
iX
it 1 v
it
Ft(L)F
t 1 G
t
(5(5))
(8(8))
(7(7))
(6(6))
Density Forecasts Density Forecasts Density forecasts of GDP growth and FS Density forecasts of GDP growth and FS
obtained estimating 99 quantile auto-obtained estimating 99 quantile auto-regressions: regressions:
These “raw” quantile estimates are These “raw” quantile estimates are “rearranged” at each date to overcome “rearranged” at each date to overcome potential “crossing” (novel application of potential “crossing” (novel application of Chernuzikhov et al. , Chernuzikhov et al. , EconometricaEconometrica 2010) 2010)
1 1ˆˆ ˆ( ) ( ) ( ) ( )( )R
t t R tGDPGQ F L GDPG
1 2ˆˆ ˆ( ) ( ) ( ) ( )( )F
t t F tFSQ F L FS
Density Forecasts (2008q3 and 2010q2) (2008q3 and 2010q2)
0.2
.4.6
.8
- 3 - 2 . 5 -2 - 1 . 5 -1 - . 5 0 .5 1 1 .5 2 2 .5 3x
k d e n s it y s r 2 0 0 8 q3 k d e n s it y s r 2 0 1 0 q 3
D e n s it y F o r e c a s t sG D P G r o w t h
0.0
2.0
4.0
6.0
8
- 3 5 - 3 0 - 2 5 - 2 0 -1 5 -1 0 - 5 0 5 1 0 1 5 2 0 2 5 3 0 3 5x
k d e n s it y s f 2 0 0 8 q 3 k d e n s it y s f 2 0 1 0 q 3
D e n s it y F o r e c a s t sF S I n d ic a t o r
U n i t e d S t a t e s
For any given
Systemic Risk Indicators Systemic Risk Indicators
(0,1)
GDPESt( )
t(GDPG
t| GDPG
tGDPaR
t( ))
FSESt( )
t(FS
t| FS
tFSaR
t( ))
Systemic Risk Fan Charts -2
02
46
1980q1 1990q1 2000q1 2010q1time
ges20 ges5
gesX = GDP Expected Shortfall with probability XSystemic Real Risk
020
40
60
1980q1 1990q1 2000q1 2010q1time
fes20 fes5
fesX = FS Expected Shortfall with probability X
Systemic Financial Risk
United States: Systemic Risk Fan Charts
Estimation and Forecasting
(details)Four steps:1) Number of factors and lags2) Quantile estimation3) Density estimates and
Expected Shortfalls4) Forecasting
(1) (1) Number of Factors and Lags
Extract all factors with eigenvalues Extract all factors with eigenvalues greater than 1greater than 1
Order factors according to the Order factors according to the explanatory power of the variance of explanatory power of the variance of the data and construct the data and construct
Choose the number of lags Choose the number of lags L L and the and the number of static factors that number of static factors that maximize BICmaximize BIC Criterion among 4 by R specifications of the FAVAR
1 1 2 1 2{( ), ( , ),...., ( , ,..., )}r r r RF F F F F F F
r F
(2) Quantile Estimation (2) Quantile Estimation
use the optimal number of lags , the number of static factors , and the estimated factors to estimate quantile auto-regressions for
specified as in (7) and (8)
address the crossing problem by adopting the “rearrangement” procedure introduced by Chernuzukhov, Fernandez-Val and Galichon (2010)
L*
r*
1,2....99
(3) Continuous Density Estimates
obtain continuous densities and compute expected shortfalls as
where is the quantile corresponding to probability and with
ES( )
1
F ( y)dy
0
1
Q( y)dy
0
Q( )
Q( ) F ( )
F ( ) inf(x | F(x) )
(4) Expected Shortfall
Regress the series of 99 quantiles to obtain the continuous function
Then, the expected shortfall estimates are
0
ˆ ˆ( )m
it i
i
Q a
2 1
0 1 20 00
1 1ˆ ˆ ˆ ˆ ˆ ˆ( ) ( ) ( ... )2 3
mmi
t t i mi
ES Q y dy a y dy a a a am
Forecasting in 3 steps
1. construct forecasts of conditional densities and of systemic risk indicators
2. use the VAR of static factors to compute dynamic forecasts k quarters ahead
3. use these forecasts are used to obtain recursive forecasts of quantile estimates
Forecast Evaluation 1
Density forecasts are satisfactory if the Probability Integral Transforms (PIT) based on estimated quantiles satisfies independence and uniformity
We constructed PITs for both our real activity and FS indicators for each of the seven countries
Properties broadly satisfied
Forecast Evaluation 2 Test based on Pearson’s Q est based on Pearson’s Q
statisticsstatistics Is the fraction of observed realizations of Is the fraction of observed realizations of
GDPG and FS close to the fractions GDPG and FS close to the fractions implied by estimated or forecast implied by estimated or forecast quantiles?quantiles?
In sample partitionsIn sample partitions [<Q5,Q5-Q10,Q10-Q20,>Q20] : [<Q5,Q5-Q10,Q10-Q20,>Q20] : left-tailleft-tail [<Q10,Q10-Q25,Q25-Q50,Q50-Q75,Q75-[<Q10,Q10-Q25,Q25-Q50,Q50-Q75,Q75-
Q90,>Q90]. Q90,>Q90]. entire distributionentire distribution Out –of- sample partition: Out –of- sample partition: [<Q20,>Q20] [<Q20,>Q20]
left tailleft tail BROADLY SATISFIEDBROADLY SATISFIED
Forecast EvaluationForecast EvaluationTable 4. Out-of–Sample Goodness of Fit
Each column reports the Q statistics corresponding to the forecast horizon k (in quarters). Significance of the Q- statistics at a 5 percent confidence level is reported in boldface.
GDPG FS k=1 k=2 k=3 k=4 k=1 k=2 k=3 k=4
U.S. 0.03 2.19 1.14 3.57 0.43 2.19 2.19 0.43 Canada 2.19 2.19 2.19 7.36 2.19 0.33 0.33 0.03 Japan 5.30 1.14 1.14 1.14 1.14 1.14 0.43 0.43 France 2.19 3.57 5.30 1.14 0.06 0.06 0.03 0.03
Germany 2.19 1.14 1.14 1.14 7.36 2.19 0.43 0.43 Italy 1.14 1.14 5.30 7.36 0.97 0.97 1.95 1.95 U.K. 2.19 0.03 0.06 1.14 2.19 0.43 0.43 0.43
Reduced-Form Stress Tests
A historical sequence of shocks to the distributions of GDP growth and the FS indicator is obtained by assuming that each quantile follows a AR(1) process
GDPGQ
t( ) a
R( ) b
R( )GDPGQ
t 1( )
tR ( )
FSQt( ) a
F( ) b
F( )GDPGQ
t 1( )
tF ( )
Reduced-Form Stress Tests Statistics
Stressed quantile series
Expected Shortfall ST deviations (ESSTDs)
STATISTICS: Average ESSTDs for each
SGDPGQ
T H ,t( ) GDPGQ
T H( )
tR ( )
, ( ) ( ) ( )FT H t T H tSFSQ FSQ
GDPES
t( ) SGDPGES
T H ,t( ) GDPES
t( )
FSES
t( ) SFSES
T H ,t( ) FSES
t( )
1...99
Average ESSTDs (2008Q1 and 2008Q2)
.4.6
.81
1.2
delta
ges
0 2 0 4 0 6 0 8 0 1 0 0q u a n t i l e
D e l t a R e a l E x p e c t e d S h o r t f a l l
46
810
12
delta
fes
0 2 0 4 0 6 0 8 0 1 0 0q u a n t i l e
D e l t a F i n a n c i a l E x p e c t e d S h o r t f a l l
U n i t e d S t a t e s : S t r e s s T e s t s 2 0 0 8 Q 1
.51
1.5
22.
5
delta
ges
0 2 0 4 0 6 0 8 0 1 0 0q u a n t i l e
D e l t a R e a l E x p e c t e d S h o r t f a l l
510
1520
2530
delta
fes
0 2 0 4 0 6 0 8 0 1 0 0q u a n t i l e
D e l t a F i n a n c i a l E x p e c t e d S h o r t f a l l
U n i t e d S t a t e s : S t r e s s T e s t s 2 0 0 8 Q 2
Structural Stress Testing At a given date, the At a given date, the sizesize of impulse of impulse
responses to identified shocks responses to identified shocks measures the measures the sensitivity of systemic risk indicators to these sensitivity of systemic risk indicators to these shocks. shocks.
Between dates, Between dates, changeschanges in the sizein the size of these of these impulse responses impulse responses provide a measure of provide a measure of changes in the changes in the resilienceresilience of an economy to these of an economy to these shocks. shocks.
The impulse responses of observable The impulse responses of observable variables can be variables can be used to detect which sectors of used to detect which sectors of the economy are most sensitive to a particular the economy are most sensitive to a particular shock (shock (risk mapsrisk maps).).
Theoretical Sign Theoretical Sign RestrictionsRestrictionsTable A. Responses of key variables to
positive shocks
Macroeconomic Model
Aggregate Supply Aggregate Demand
GDP growth Positive Positive
Inflation Negative Positive
Banking Model Bank Credit Demand
Bank Credit Supply
Bank Credit Growth Positive Positive
Change in Lending Rates
Positive Negative
IdentificationIdentification
InIn all all countries all identified shocks countries all identified shocks are are aggregateaggregate demand shocksdemand shocks associated with associated with bank credit bank credit demand shocksdemand shocks
Consistent with results in Canova Consistent with results in Canova and De Nicolò (JIE 2003) and De Nicolò (JIE 2003)
Slowdowns in aggregate bank credit Slowdowns in aggregate bank credit growth are the results of real growth are the results of real activity downturns (consistent with activity downturns (consistent with Berrospide and Edge, 2010)Berrospide and Edge, 2010)
A Simple Example of A Simple Example of Structural Stress TestStructural Stress Test
Gauge weather the stress test signals lower Gauge weather the stress test signals lower resilience to structural shocks in the G-7 resilience to structural shocks in the G-7 economies economies priorprior to 2007Q3 (pre-crisis)to 2007Q3 (pre-crisis)
Compute the Compute the differencedifference of the cumulative of the cumulative impact of the impulse response functions of impact of the impulse response functions of GDPESGDPES and and FSESFSES to each structural shock to each structural shock estimated for (1980Q1-2007Q2) and estimated for (1980Q1-2007Q2) and (1993Q2-2007Q2) (1993Q2-2007Q2)
A positive difference would indicate a lower A positive difference would indicate a lower resilience of the economies to these shocksresilience of the economies to these shocks
Results Results In all countries the first two shocks become
predominant in the last sub-period
Increased risk concentrations in these economies on both the real and financial sides
The U.S. economy had increased its vulnerability to shocks both on the real and financial sides, in absolute terms as well as relatively to the other G-7 economies
Modeling DevelopmentsModeling Developments
Extension of our framework to the simultaneous modeling of countries and regions of the world
Refinement of stress testing statistics and construction of risk maps