Calibrating a Barrier Model
A barrier model describes the event of default as the first time the market value of the firm falls below a critical value. For special cases a closed form solution exists. In general a simulation approach is used.
There are a number of issues that must be settled before running a simulation.
Part (A)
How do you determine the value of the firm, A(t0) ?
Part (B)
How do you determine the volatility of the describing the change in firm value, σ?
Part (C)
How do you determine the level of the barrier?