In this article we consider Bayesian parameter inference associated to
partially-observed stochastic processes that start from a set B0 and are
stopped or killed at the first hitting time of a known set A. Such processes
occur naturally within the context of a wide variety of applications. The
associated posterior distributions are highly complex and posterior parameter
inference requires the use of advanced Markov chain Monte Carlo (MCMC)
techniques. Our approach uses a recently introduced simulation methodology,
particle Markov chain Monte Carlo (PMCMC) (Andrieu et. al.
This article establishes sufficient conditions for a linear-in-time bound on
the non-asymptotic variance of particle approximations of time-homogeneous
Feynman-Kac formulae. These formulae appear in a wide variety of applications
including option pricing in finance and risk sensitive control in engineering.
In direct Monte Carlo approximation of these formulae, the non-asymptotic
variance typically increases at an exponential rate in the time parameter.