5.2.7 Measuring ECL – Explanation of inputs, assumptions and estimation techniques
Measuring ECL – Explanation of inputs, assumptions and estimation techniques
The Expected Credit Loss (ECL) is measured on either a 12-month (12M) or Lifetime basis depending whether a significant increase in credit has occurred since initial recognition or whether an asset is considered to be credit-impaired. Expected credit losses are the discounted product of the Probability of Default (PD), Exposure at Default (EAD), and Loss Given Default (LGD), defined as follows:
- The PD represents the likelihood of a borrower defaulting on its financial obligation (as per ‘Definition of default and credit-impaired’ above), either over the next 12 months (12M PD), or over the remaining lifetime (Lifetime PD) of the obligation.
- EAD is based on the amounts the Group expected to be owed at the time of default, over the next 12 months (12M EAD) or over the remaining lifetime (Lifetime EAD). For example, for a revolving commitment, the Group includes the current drawn balance plus any further amount that is expected to be drawn up to the current contractual limit by the time of default, should it occur.
- Loss Given Default (LGD) represents the Group’s expectation of the extent of loss on a defaulted exposure. LGD varies by type of counterparty, type and seniority of claim and availability of collateral or other credit support. LGD is expressed as a percentage loss per unit of exposure at the time of default (EAD). LGD is calculated on a 12-month or lifetime basis, where 12-month LGD is the percentage of loss expected to be made if the default occurs in the next 12 months and Lifetime LGD is the percentage of loss expected to be made if the default occurs over the remaining expected lifetime of the loan.
The ECL is determined by projecting the PD, LGD and EAD for each future month and for each individual exposure or collective segment. These three components are multiplied together and adjusted for the likelihood of survival (i.e. the exposure has not prepaid or defaulted in an earlier month). This effectively calculates an ECL for each future month, which is then discounted back to the reporting date and summed. The discount rate used in the ECL calculation is the original effective interest rate or an approximation thereof.
The lifetime PD is developed by applying a maturity profile to the current 12M PD. The maturity profile looks at how defaults develop on a portfolio from the point of initial recognition throughout the lifetime of the loans. The maturity profile is based on historical observed data and is assumed to be the same across all assets within a portfolio and credit grade band. This is supported by historical analysis.
The 12-month and lifetime EADs are determined based on the expected payment profile, which varies by product type.
- For amortizing products and bullet repayments loans, this is based on the contractual repayments owed by the borrower over a 12 month or lifetime basis. This will also be adjusted for any expected overpayments made by a borrower. Early repayment/refinance assumptions are also incorporated into the calculation.
- For revolving products, the exposure at default is predicted by taking current drawn balance and adding a “credit conversion factor” which allows for the expected drawdown of the remaining limit by the time of default. These assumptions vary by product type and current limit utilization based on analysis of the Group’s recent default data.
Forward-looking economic information is also included in determining the 12-month and lifetime PD. These assumptions vary by product type. Refer to the Note below for an explanation of forward-looking information and its inclusion in ECL calculations.
These assumptions underlying the ECL calculation – such as how the maturity profile of the PDs and how collateral values change etc. – are monitored and reviewed on a quarterly basis.
There have been no significant changes in estimation techniques or significant assumptions made during the year.