Travail de recherche/Working paper
| Résumé : | The volatility estimation is a crucial problem for pricing derivatives. The traditional implied volatility approach induces the undesired smile effect and is therefore inconsistent with the market reality. A second more realistic approach is due to Bensoussan, Crouhy and Galai (1995) who derive an extension of the Black-Scholes model where the stochastic volatility ? is endogenous and depends on the change in the firm’s financial leverage. These authors give an analytic approximation for ? when the firm is financed by external funds such as debts, under the assumptions that the risk-free rate and the volatility of the return on the firm’s asset are constant. In this work, we will generalize this result by allowing these parameters to be variable. |
