Explanation

Reduced-form models (also known as intensity-based models) of corporate credit risk:

• Option A is correct: Reduced-form models can explain the economic reason for default. These models use observable market variables and economic indicators to model default intensity.

Key characteristics of reduced-form models:

• Treat default as an exogenous event
• Model default intensity (hazard rate) as a function of observable variables
• Can incorporate macroeconomic factors, industry conditions, and firm-specific variables
• Provide economic explanations for default probabilities
• More flexible than structural models for empirical implementation

Reduced-form models are particularly useful because they can incorporate a wide range of economic factors that influence default probabilities, making them effective at explaining the economic reasons behind credit risk.