The Forward Search is an iterative algorithm concerned with detection of outliers and other unsuspected structures in data. This approach has been suggested, analysed and applied for regression models in the monograph Atkinson and Riani (2000). An asymptotic analysis of the Forward Search is...

In the application of autoregressive models the order of the model is often estimated using either a sequence of likelihood ratio tests or a likelihood based information criterion. The consistency of such procedures has been discussed extensively under the assumption that the characteristic...

Analysis of economic time series often involves correlograms and partial correlograms as graphical descriptions of temporal dependence. Two methods are available for computing these statistics: one based on autocorrelations and the other on scaled autocovariances. For stationary time series the...

Many real life regression problems exhibit some kind of calender time dependency and it is often of interest to predict the behavior of the regression function along this calender time direction. This can be formulated as a regression model with an added latent time series and the task is to be...

When analysing cointegration in vector autoregressive models it is usually assumed that (i) the number of cointegrating relations is not smaller than what is tested for, (ii) the number of unit roots equals the number of common stochastic trends, and (iii) the remaining characteristic roots of...

A vector autoregressive model allowing for unit roots as well as explosive characteristic roots is developed. The Granger-Johansen representation shows that this results in processes with two common features: a random walk and an explosively growing process. Co-integrating and co-explosive...