The behaviour of the likelihood function for ARMA models

The paper deals with some properties of the (Gaussian) likelihood function for multivariable ARMA models. Its behaviour at the boundary of the parameter space is described; its continuity properties as well as the question of the existence of a maximum are discussed. We have not been able to show in...

Ausführliche Beschreibung

Bibliographische Detailangaben
Link(s) zu Dokument(en):IHS Publikation
Hauptverfasser: Deistler, Manfred, Pötscher, B. M.
Format: Article in Academic Journal PeerReviewed
Veröffentlicht: Cambridge University Press 1984
Beschreibung
Zusammenfassung:The paper deals with some properties of the (Gaussian) likelihood function for multivariable ARMA models. Its behaviour at the boundary of the parameter space is described; its continuity properties as well as the question of the existence of a maximum are discussed. We have not been able to show in general the existence of the maximum over the usual parameter spaces. However, the maximum always exists over a suitably enlarged parameter space (given that the data are non-degenerate), which includes parameters corresponding to processes with discrete spectral components.