What does the default trigger in the Merton model represent?

• A. The portion of a firm’s total asset value above liability
• B. The face value of a zero-coupon bond
• C. The market value of a firm’s equity
• D. The maximum allowable debt level

Answer: (B)

In the context of the Merton model, the default trigger specifically represents the level of the firm's asset value at which it would be unable to meet its obligations. This model is often used to assess the credit risk of a company by treating its equity as a call option on its assets.

The default trigger is equivalent to the face value of a zero-coupon bond that matures at a certain point. This zero-coupon bond represents the liability that must be serviced by the firm. If the firm's total asset value falls below this threshold (the face value of the zero-coupon bond), then default occurs since the firm does not have sufficient assets to cover its outstanding liabilities. Thus, the default trigger serves as a critical parameter for determining the boundaries of default risk within the Merton framework.

Understanding this concept is pivotal in analyzing credit risk and the likelihood of default, making it an essential component of the Merton model and alternative investment analysis.