Norway experienced a high immigration flow after the EEA directive in 2004 stating workers right to free movement within the European Union and EEA-countries. There is no clear consensus in the literature on how immigration affects native wages, but some studies using Norwegian micro data have...

We study the algebraic structure of an I(d) vector autoregressive process, where d is restricted to be an integer. This is useful to characterize its polynomial cointegrating relations and its moving average representation, that is to prove a version of the Granger representation theorem valid...

We study large-sample properties of likelihood ratio tests of the unit root hypothesis in an autoregressive model of arbitrary, finite order. Earlier research on this testing problem has developed likelihood ratio tests in the autoregressive model of order one, but resorted to a plug-in approach...

This paper presents optimum simple step-stress plans under the log-logistic cumulative exposure model. The likelihood function of the model parameters is derived, from which the Fisher information matrix and the asymptotic variance of the reliability estimate are obtained. Optimum times of...

The Birnbaum–Saunders distribution is useful for modeling reliability data. In this paper we obtain adjusted profile maximum likelihood estimators for the Birnbaum–Saunders distribution shape parameter under type II data censoring. We consider the adjustments to the profile likelihood...