This paper proposes Markov Modulated Poisson process, which the underlying state is
governed by a homogenous Markov chain to model the arrival process for catastrophic events.
Further, we propose a generalization of Radon-Nikodym processes that a changing measure
corresponds to a change of drift for the underlying Brownian motion and a change of the
stochastic intensity for the Markov jump diffusion model. By the change of measure, the
pricing formula and dynamic hedging for CatEPut are derived and our pricing formula could
reduce to Cox, Fairchild, and Pedersen (2004) and Jaimungal and Wang (2006).