Feasible parameter regions for alternative discrete state space models

This paper provides a comparison of a parameter-driven and an observation-driven discrete state space model. The two models are shown to have non-overlapping feasible regions for dispersion and first-order autocorrelation. with the region for the parameter-driven model being much larger than that of the observation-driven model, as well as providing a much better representation of the empirical moments of observed count series. (C) 2008 Elsevier B.V. All rights reserved.