This article postulates a flexible specification for the implied volatility surface, which accounts for the existence of volatility skew and term structure. I show that it is possible to express the local volatility function in terms of the implied volatility. I then obtain an analytic formula...

Empirical evidence shows that, in equity options markets, the slope of the skew is largely independent of the volatility level. Single-factor stochastic volatility models are not flexible enough to account for the stochastic behavior of the skew. On the other hand, multifactor stochastic...