  A dynamic factor model with factor series following a VAR$(p)$ model is shown
to have a VARMA$(p,p)$ model representation. Reduced-rank structures are
identified for the VAR and VMA components of the resulting VARMA model. It is
also shown how the VMA component parameters can be computed numerically from
the original model parameters via the innovations algorithm, and connections of
this approach to non-linear matrix equations are made. Some VAR models related
to the resulting VARMA model are also discussed.
