Free CAIA Level II Methods and Models Practice Questions

D is correct. In the KMV model, distance to default measures how many standard deviations of asset value change separate the firm's current asset value from the default point (typically defined as short-term debt plus half of long-term debt). A larger DD implies a lower probability of default.
Choice B is incorrect because the credit spread measures the yield premium over the risk-free rate; it is an output of reduced-form models, not the KMV distance to default.
Choice C is incorrect because the probability of equity falling to zero is not how KMV defines distance to default; DD is expressed in standard deviation units, not as a probability.
Choice A is incorrect because the debt-to-market-cap ratio is a leverage metric, not the KMV distance to default measure.

D is correct. A key innovation of KMV is the use of a large proprietary database of actual default histories to translate the theoretical distance to default into an empirical expected default frequency (EDF). This overcomes the Merton model's reliance on the normal distribution assumption for mapping DD to default probabilities.
Choice A is incorrect because assuming a flat term structure is a simplification common to the original Merton framework, not an improvement introduced by KMV.
Choice C is incorrect because KMV, like Merton, relies on the market value of assets estimated via equity market prices and option-pricing relationships, not book value.
Choice B is incorrect because KMV still requires an estimate of asset volatility; it uses equity market data and an iterative process to back out asset volatility from observed equity values.

C is correct. Reduced-form models are highly flexible and can be calibrated to fit the observed term structure of credit spreads without requiring knowledge of firm asset dynamics. However, they treat default as an exogenous surprise and offer less economic intuition about what drives default compared to structural models. Empirical models like the Z-score are simple and historically well-validated but rely on financial statement data and may lag real-time market developments.
Choice A is incorrect because the KMV model requires market equity prices and volatility to estimate asset values and is therefore better suited to public firms, not private ones. Reduced-form models infer default intensity from bond or CDS prices, not from equity volatility.
Choice B is incorrect because the Z-score uses accounting ratios rather than real-time market data, making it less timely than market-based approaches. Structural models are not inherently better for speculative-grade issuers.
Choice D is incorrect because KMV does not eliminate estimation error; asset value and volatility must still be estimated through an iterative equity-option inversion. Default intensity in reduced-form models is inferred via calibration, not directly observed.