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Agenda. Concept Methodology of estimationResults (just for illustration)Margin of conservatismCostsConclusion. Introduction. LGD: one of the three parameters (PD, LGD, EAD) in IRB approach for retailUnexpected Loss and Minimum capital reserve required proportional to LGDPragmatic approachJu
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1. Estimation of the Loss Given Default (LGD) – Retail Portfolio
2. Agenda Concept
Methodology of estimation
Results (just for illustration)
Margin of conservatism
Costs
Conclusion
3. Introduction LGD: one of the three parameters (PD, LGD, EAD) in IRB approach for retail
Unexpected Loss and Minimum capital reserve required proportional to LGD
Pragmatic approach
Just a calculation method
Neither statistical segmentation nor model
In the underlying Merton model of Basel 2 formulas, only E(LGD) is expected. An individual estimation of LGD is not required.
Use of the historical data available
For retail portfolio
4.
Definitions
(DIRECTIVE 2006/48/EC, 14 June 2006, article 4)
‘loss’ means economic loss, including material discount effects, and material direct and indirect costs associated with collecting on the instrument;
‘loss given default (LGD)’ means the ratio of the loss on an exposure due to the default of a counterparty to the amount outstanding at default;
Concept
5. Calculation
Basic loss : = EAD (exposure at default)
– recoveries (all over the period of default)
+ increases of exposure (all over the period of default)
Economic loss: add discount effects and costs (human resources…)
Increases include
drawing after default (not in the CCF parameter)
costs
Concept
6. Calculation
where j >=0, at default, j=0 :
EAD = exposure at default
C*j = increases of period j, converted to current value (at default) with rate r.
R*j = recoveries of period j, converted to current value (at default) with rate r.
cs indirect costs (% of exposure) – set, same for all exposures
Concept
7. Illustration on a theoretical case (overdraft on a bank account):
Basic Loss = Exposure at default – recovery flow + increase flow
= 300 – 200 + 30 = 130
Discount effects (rate: 15%)
“Discounted” loss = EAD – converted to current value recovery flow
+ converted to current value increase flow
= 300 – (200/1.15) + (30/1.15) = 300 – 174 + 26 = 152
Indirect costs : 10 € for mail, 3% of EAD
Add a margin of conservatism if necessary
Concept
8. Illustration on real data:
1st example – mortgage, default in December 2004, loss in January 2005
Concept
9. Illustration on real data :
2nd example – Mortgage, default in October 2003, last recovery in March 2004
Discount rate : 7.5% (1 year), or 0.6% (1 month)
Concept
10. Conversion to current value: choice of the rate
Not detailed in Basel 2 Framework
Choice of Group: real interest rate of the loan
Coherence with IFRS
Conversion with a monthly step
Horizon
Recovery observed on 10 years
All recovery flows coming after 10 years are considered as lost
Methodology
11. Practical calculation – individual level
Division in 10 years of recovery
Year 0 = 12 months following default
Year 1 = 13 to 24 months following default
…
Year 9 = 108 to 120 months following default
Look at every period j, from 0 to 9 years, of
Recovery flows, converted to current value (Rj*)
Increase flows, converted to current value (Cj*)
Amount still to recover at the beginning of period j (RRj*)
At default, j=0 and RR0 = EAD
After default RRj = RRj-1 – R*j-1 + C*j-1
marginal rate of recovery, on period j
?j = (R*j - C*j) / RRj-1
Calculation of a rate of no recovery at 10 years (Kaplan-Meier estimator)
Methodology
12. Aggregation of flows – Vintage matrix
By category of product and by generation of default
construction of matrix giving the dynamic of recoveries for each generation of default (A generation groups all loans or overdrafts in default at the same time, year, quarter or month)
Still to recover
Marginal rate
LGD
Methodology
13. Truncated and censored data
The oldest generations aren’t observed since default => left truncation
The youngest generations are still in default and not closed => right censoring
They take part to the calculation while they are observed
Methodology
14. Advantages of the method:
All observations can take part to the estimation, including when data are censured or truncated
Marginal rates can easily be “backtested”
An estimation of LGD depending of age in default can be produced:
After j periods in default:
Segmentation
By category of product, type of guarantee, age in default
Not a statistical model Methodology
15. Margin of conservatism
Reasons of adding a margin of conservatism
Lack of robustness (low numbers of data)
Temporal volatility (changing in organization, big amounts…)
Economic cycle (downturn LGD)
Methods to treat these uncertainties
Bootstrap
1000 random draws
quantile : 95%
Sampling (elimination of 5% of quarterly generations with the better marginal rate) Methodology
16. Bootstrap
Recent method (1979 - B. EFRON) based on data simulation
Sampling with replacement, where sample size is the same as the original dataset. Each sample simulate new “stressed” data.
Estimation of LGD on all these samples
Distribution of empirical statistics, and quantiles giving a confidence interval.
Methodology
17. Additional margin
For approximations done during estimation, intended for disappearing. They can lead to errors in estimation, that is why a margin is added to regulatory margin of conservatism.
Examples of approximations identified:
Entity bias (estimation on 10 regional banks among 25)
Loss registered in commercial agency, not available in data
Exact Basel default not available in historical data, approximation with other close notions
Methodology
18. Costs Costs entered:
From litigation department
3 types of costs:
Human resources (70%)
Customers (25%)
Regular costs (5%)
Methodology:
Average cost of litigation (by loan)
Average exposure at default (by loan)
Results (illustration for example)
19. Results
For confidential reasons, the results are changed…
Big impact of indirect costs and margin of conservatism
Results
20. Illustration on theoretical data:
Marginal Recovery Rate on 10 years - Mortgage
Results
21. Graphic illustration
Results
22. Results Results by age of default
23. Conclusion Link with provisions
For exposures in default (with PD = 100%), comparison between LGD and provisions, with impact on RWA
For all exposures, comparison between LGD and provisions, with impact on capital
Interactions with accounts department
Link with economic capital
Use of single factor models, like in Basel 2 framework
LGD still an fundamental parameter
May be adjusted (margin less conservative)