29 - Risk Measurement and Reporting Flashcards
How are risks quantified?
By assessing their frequency and severity.
Why is it difficult to model low frequency events?
There is a lack of data.
How is operational risk usually quantified?
- Broad-brush addition to other risks
2. Scenario analysis
In which circumstance is scenario analysis the most useful?
When it is difficult to fit full probability distributions to risk events.
What steps are involved in scenario analysis?
- Grouping risks into broad categories
- Development of a plausible adverse scenario
- Calculation of the consequences of the risk event occurring for each scenario.
- Total costs calculated are taken as the financial cost of all risks represented by the chosen scenario.
Give a drawback of a scenario testing approach.
The approach focuses on severity and neglects the probability of the scenario occurring.
Selection of the scenarios is subjective and non-exhaustive
Define: Stress Testing
Involves testing for weaknesses in a portfolio by subjecting it to extreme market movements or credit or liquidity risk events.
Give two types of stress tests.
- To identify ‘weak areas’ in the portfolio and investigate the effects of localised stress situations by looking at the effect of different combinations of correlations and volatilities
- To gauge the impact of major market turmoil affecting all model parameters while ensuring consistency between correlations while they are ‘stressed’
Describe a ‘reverse stress test’
The construction of a severe stress scenario that just allows the firm to be able to continue to meet its business plan. The scenario may be extreme but it should be plausible.
Give the limitations usually applied to stochastic modelling with regards to stress testing.
- restricting the duration or time horizon of the model
- Limit the number of variables modelled stochastically and use a deterministic approach for the other variables.
3, Carry out a number of runs with a different single stochastic variable and then a single deterministic run using all the worst case scenarios together.
How is risk aggregation, to allow for correlations and inter-actions, usually performed?
- Stochastic modelling - although impractical
- Simple formulae if risk events are fully dependent or fully independent.
- Correlation matrices
- Copulas
Give the main advantage and main disadvantage of risk aggregation.
Pro: combining risks may result in a lower total risk through diversification
Con: The time to run adequate models may be too long and this may restrict the number of scenarios that can be modelled.
Give a measure of the risk taken for a passive portfolio.
Historic tracking error and forward-looking tracking error.
How are liability risks measured?
By carrying out analysis of actual vs expected experience
Give examples of deterministic approaches to measuring risks.
- Notional approach
- Factor sensitivity approach
- Scenario sensitivity