FRM Part I · FRM Exam Part I · Machine-Learning Methods
A risk analyst fits a regression of credit spread changes on 40 candidate predictors using only 120 observations. The ordinary least squares model fits the training data almost perfectly but forecasts poorly out of sample. Which approach most directly addresses this problem by adding a penalty on the size of the coefficients?
Ridge or LASSO regularization is correct because these methods add a penalty on coefficient size, shrinking estimates and reducing variance. With many predictors relative to observations, OLS overfits, and the penalty improves out-of-sample forecasting performance, whereas adding predictors would worsen overfitting.
- AAdding more predictors to the model
- BUsing ridge or LASSO regularizationCorrect
- CIncreasing the number of training epochs
- DRemoving the intercept from the model
Explanation
The model is overfitted because the number of predictors is large relative to observations. Ridge and LASSO add a penalty on coefficient size, shrinking coefficients and reducing variance. Adding predictors would worsen overfitting, and the other options do not penalize coefficients.
Did you get it right without looking?
One question tells you little. A timed set on Machine-Learning Methods shows your real accuracy, how long you take and where you lose marks.
More Machine-Learning Methods questions
- A model predicting loan losses achieves a mean squared error of 0.5 on the training sample but 4.0 on a held-out validation sample. Which in…
- A bank's compliance team has millions of unlabelled transaction records and wants an algorithm to group them into segments of similar behavi…
- A default classifier is tested on 200 loans. Results: 30 true positives, 10 false positives, 20 false negatives, and 140 true negatives. Wha…
- A risk analyst has a dataset of 50,000 past loan applications, each described by borrower income, debt-to-income ratio and loan size, togeth…
- An analyst splits 1,000 observations as follows: 600 for training, 200 for validation and 200 for testing. She trains five candidate models …
- An analyst tunes a regularization penalty in a ridge-type regression. As the penalty parameter is increased from a very small value to a ver…