Before revision:  We consider a company whose cumulative net revenues evolve as a drifted Brownian motion modulated by a finite state Markov chain, and model the discount rate as a deterministic function of the current state of the chain.
After revision:  We consider a company whose cumulative net revenues evolve as a Brownian motion with positive drift that is modulated by a finite state Markov chain, and model the discount rate as a deterministic function of the current state of the chain.