文摘
We investigate a Verhulst process, which is a particular functional of geometric Brownian motion and has many applications, among others, in biology and in stochastic volatility models. We present a representation of the density of one-dimensional distribution of Verhulst process. The closed formula for the density of Verhulst process simplifies in the case where the drift of the geometric Brownian motion is equal to ?/2. Some special properties of this process are discussed; in particular, it turns out that, under Girsanov’s change of measure, a Verhulst process still remains a Verhulst process, although with other parameters.