FRM Part II · FRM Exam Part II · Beyond Exceedance-Based Backtesting of Value-at-Risk Models
Why is backtesting ES generally considered more demanding in data terms than backtesting VaR at the same confidence level?
ES is the average loss in the tail, and only a few observations fall there. With so little tail data, estimates are noisy and statistical tests have low power, making ES backtesting harder than simply counting VaR exceedances.
- AES is computed at a higher confidence level than VaR by regulation
- BES requires normality of returns, which VaR does not
- CES depends on the average of losses in the tail, so few tail observations leave the estimate and tests with low statistical powerCorrect
- DES cannot be computed using historical simulation
Explanation
ES averages losses beyond VaR, and tail observations are scarce, so test statistics are noisy and have low power. ES does not require normality and can be computed by historical simulation. The confidence level is a separate choice.
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 team backtests two 99% VaR models using only the count of exceedances over 500 days. Both models record 5 exceedances, yet one model'…
- A bank backtests a 99% daily VaR over 250 days with 2.5 expected exceedances. It observes 3 exceedances, but all 3 occurred in consecutive d…
- A validator runs a Berkowitz test and rejects the null. Estimated parameters show mu close to 0 and sigma^2 close to 1, but rho is estimated…
- A risk manager computes PIT values for a 10-day-ahead VaR model using overlapping daily forecasts, then applies a standard Kolmogorov-Smirno…
- Which of the following is a recognized approach that goes beyond simple exception counting to address the fact that exceedance-based backtes…
- 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,…