FRM Part II · FRM Exam Part II · Beyond Exceedance-Based Backtesting of Value-at-Risk Models
A bank's two VaR models both pass the Kupiec unconditional coverage test at 99%, each with 2 or 3 exceedances in 250 days. A validator wants to decide which is better. Which approach is most appropriate under a scoring-function framework?
The validator should compare average scores from a consistent scoring function and test whether the difference is statistically significant. Coverage tests only check pass or fail, while scores use loss magnitude and penalise both breaches and excess conservatism, enabling a meaningful ranking.
- ACompare their average scores from a consistent scoring function and test whether the difference is statistically significantCorrect
- BSelect the model with the higher average VaR, since it is safer
- CSelect the model with fewer exceedances regardless of loss size
- DChoose the model whose VaR is less volatile over time
Explanation
Passing coverage tests does not discriminate between models. A consistent scoring function evaluated on losses lets the validator rank models, and a significance test on the score difference checks that the ranking is not noise. Higher VaR is penalised for conservatism, and exceedance count ignores magnitude.
Did you get it right without looking?
One question tells you little. A timed set on Beyond Exceedance-Based Backtesting of Value-at-Risk Models shows your real accuracy, how long you take and where you lose marks.
More Beyond Exceedance-Based Backtesting of Value-at-Risk Models questions
- A risk manager has PIT values u_t from a VaR model and wants to test the full distribution rather than just tail exceedances. She transforms…
- A bank's VaR model passes a standard 99% exceedance-count test over 250 days, with 2 exceedances. A PIT backtest of the same model, however,…
- A bank has a 99% VaR model that produced zero exceedances in 250 days. Which interpretation is most consistent with the limitations of excee…
- When using a scoring function to compare competing VaR forecasts, which property makes a scoring function 'strictly consistent' for the quan…
- A risk analyst evaluates a bank's daily 99% VaR model using the probability integral transform (PIT). For each day, she computes the value o…
- Two models forecast 97.5% ES for a portfolio. Model A and Model B both pass a standard exceedance-count test on VaR at 97.5%. Over the sampl…