Utility Maximization of the Exponential Lévy Switching Models

Theory of Probability &Its Applications, Volume 69, Issue 1, Page 127-149, May 2024.
This article is devoted to maximization of HARA (hyperbolic absolute risk aversion) utilities of the exponential Lévy switching processes on a finite time interval via the dual method. The description of all $f$-divergence minimal martingale measures and the expression of their Radon--Nikodým densities involving the Hellinger and Kulback--Leibler processes are given. The optimal strategies in progressively enlarged filtration for the maximization of HARA utilities as well as the values of the corresponding maximal expected utilities are derived. As an example, the Brownian switching model is presented with financial interpretations of the results via the value process.