Nonstationary time series arising from autoregressice models with roots on or near the unit circle have been an intensive subject of econometric reseach during the last twenty years. Heikki Kauppi's doctoral dissertation deals with several topics in the area of theoretical econometrics of...

In some cases the unit root or near unit root behavior of linear autoregressive models fitted to economic time series is not in accordance with the underlying economic theory. To accommodate this feature we consider a threshold autoregressive process with the threshold effect only in the...

There has been serious suspicion of a spurious rejection of the unit roots in panel studies of PPP due to the failure to control cross-sectional dependence. This article presents evidence of mean-reversion in industrial country real exchange rates in a set up that accounts for cross-sectional...