The likelihood of multivariate GARCH models is ill-conditioned

The likelihood of multivariate GARCH models is ill-conditioned because of two facts. First, financial time series often display high correlations, implying that an eigenvalue af the conditional covariances fluctuates near the zero boundary. Second, GARCH models explain conditional covariances in ter...

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Detalles Bibliográficos
Autores: Jerez Méndez, Miguel, Casals Carro, José, Sotoca López, Sonia
Tipo de recurso: informe técnico
Fecha de publicación:1999
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/64224
Acceso en línea:https://hdl.handle.net/20.500.14352/64224
Access Level:acceso abierto
Palabra clave:ARCH
GARCH
Maximum-likelihood.
Análisis Multivariante
1209.09 Análisis Multivariante
Descripción
Sumario:The likelihood of multivariate GARCH models is ill-conditioned because of two facts. First, financial time series often display high correlations, implying that an eigenvalue af the conditional covariances fluctuates near the zero boundary. Second, GARCH models explain conditional covariances in terms of a linear combination of delayed squared errors and their conditional expectation; this functional form implies that the likelihood function is almost flat in the neighborhood of the optimal estimates. Building on this analysis we propose a linear transformation of data which, not only stabilizes the likelihood computation, but also provides insight about the statistical properties of data. The use of this transfonnation is illustrated by modeling the short-run conditional correlations of four nominal exchange rates.