Fitting inhomogeneous phase-type distributions to data: the univariate and the multivariate case
share
The class of inhomogeneous phase-type distributions was recently introduced as a dense extension of classical phase-type distributions that leads to more parsimonious models in the presence of heavy tails. In this paper we propose a fitting procedure for this class to given data. We furthermore consider an analogous extension of Kulkarni's multivariate phase-type class to the inhomogeneous framework and study parameter estimation for the resulting new and flexible class of multivariate distributions. As a by-product, we amend a previously suggested fitting procedure for the homogeneous multivariate phase-type case and provide appropriate adaptations for censored data. The performance of the algorithms is illustrated in several numerical examples, both for simulated and real-life insurance data.
READ FULL TEXT