Structural results for partially observed control models

A general partially observed control model with discrete time parameter is investigated. The present main interest concerns monotonicity results and bounds for the value functions and for optimal policies. In particular, the paper shows how the value functions depend on the observation kernels and it presents conditions for a lower bound of an optimal policy. The approach is based on two multivariate stochastic orderings: the TP2 ordering and the Blackwell ordering.