Cornerstone

Quantitative Methods

CFA® Level II, published weight 5–10%. Multiple regression, misspecification, time series, machine learning.

What the outline covers

Sample questions

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Question 1

A multiple regression reports a significant F-statistic but no individually significant t-statistics. This most likely indicates:

A. Heteroskedasticity
B. Serial correlation
C. Multicollinearity
D. A unit root

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C. Multicollinearity inflates the standard errors of individual coefficients while leaving the joint explanatory power intact — exactly this signature.

Reading: Quantitative Methods — Model Misspecification, LOS 3.b

Question 2

Adding a variable to a regression raises R² from 0.42 to 0.44 but lowers adjusted R² from 0.39 to 0.38. The analyst should conclude the variable:

R²: 0.42 → 0.44 · R̄²: 0.39 → 0.38

A. Improves the model and should be retained
B. Does not justify its loss of degrees of freedom
C. Introduces heteroskedasticity
D. Makes the model non-stationary

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B. R² always rises with an added regressor. A falling adjusted R² means the explanatory gain does not compensate for the lost degree of freedom.

Reading: Quantitative Methods — Evaluating Regression Model Fit, LOS 2.c

Question 3

An AR(1) model is estimated on a series with a unit root. The most appropriate remedy is to:

A. Add a lag to the model
B. First-difference the series
C. Use White-corrected standard errors
D. Apply a log transformation to the dependent variable

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B. A unit root violates covariance stationarity and produces spurious results. First differencing typically restores stationarity.

Reading: Quantitative Methods — Time-Series Analysis, LOS 5.f

Question 4

Conditional heteroskedasticity in a regression most directly causes:

A. Biased coefficient estimates
B. Unreliable standard errors and invalid t-tests
C. A spurious unit root
D. Perfect multicollinearity

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B. Coefficients remain unbiased and consistent, but the standard errors are wrong, so hypothesis tests based on them are invalid.

Reading: Quantitative Methods — Model Misspecification, LOS 3.a

Question 5

A machine learning model shows very low training error and substantially higher validation error. This is best described as:

A. Underfitting
B. Overfitting
C. Data leakage
D. Correct generalisation

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B. A large gap between training and validation performance means the model has fitted noise in the training sample rather than signal.

Reading: Quantitative Methods — Machine Learning, LOS 6.c

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