We consider two multivariate long-memory ARCH models, which extend the univariate long-memory ARCH models, we first consider a long-memory extension of the restricted constant conditional correlations (CCC) model introduced by Bollerslev (1990), and we propose a new unrestricted conditional...

In a model with private information of the worker about her ability and unobservable effort choice, the role of public and private employment services is analyzed. The coexistence of an inefficient employment exchange and an efficient private agency may lead to optimal screening with first best...

Multivariate Volatility Models belong to the class of nonlinear models for financial data. Here we want to focus on multivariate GARCH models. These models assume that the variance of the innovation distribution follows a time dependent process conditional on information which is generated by...

Correspondence analysis (CA) is a descriptive method which allows us to analyze and to XploRe the structure of contingency tables (or, by extension, non-negative tables where rows and columns are the entities of interest). It is similar to principal cornponent analysis (PCA) in the sense that,...

The small sample properties of two types of Chow tests are investigated in the context of multiple time series models. It is found that the tests may have substantially distorted size if the sample size is not large relative to the number of parameters in the model under study. In particular the...

This paper derives conditions for the existence of fourth moments of multivariate GARCH processes in the general vector specification and gives explicit results for the fourth moments and autocovariances of the squares and cross-products. Results are provided for the kurtosis and co-kurtosis...