The present paper considers Dickey-Fuller-type unit root tests which account for a structural break occurring at an unknown point in time. The break is modelled by an innovational outlier approach. Provided that the break date is estimated correctly, the exact invariance to a mean and a slope...

This paper investigates the time-series properties of the price of iron ore. The focus is on testing a unit-root null hypothesis against a trend-stationary alternative, with a structural break allowed under both hypotheses. We consider unit-root tests with or without structural breaks, applied...

We show that the CUSUM-squared based test for a change in persistence by Leybourne et al. (2007) is not robust against shifts in the mean. A mean shift leads to serious size distortions. Therefore, adjusted critical values are needed when it is known that the data generating process has a mean...

The occurrence of unit roots in economic time series has far reaching consequences for univariate as well as multivariate econometric modelling. Therefore, unit root tests are nowadays the starting point of most empirical time series studies. The oldest and most widely used test is due to Dickey...

This note shows that German real GDP follows a trend-stationary process. Both tests which have trend-stationarity as the alternative hypothesis as well as tests that have it under the null hypothesis prefer the trend-stationary model. Explicit consideration of breaks in the trend is not...

This paper considers forecast averaging when the same model is used but estimation is carried out over different estimation windows. It develops theoretical results for random walks when their drift and/or volatility are subject to one or more structural breaks. It is shown that compared to...

Hours worked is a time series of interest in many empirical investigations of the macroeconomy. Estimates of macro elasticities of labour supply, for example, build on this variable. Other empirical applications investigate the response of hours worked to a shock to technology on the basis of...

To assess the effects of the EMU on inflation rate dynamics of its member states, the inflation rate series for 21 European countries are investigated for structural changes. To capture changes in mean, variance, and skewness of inflation rates, a generalized logistic model is adopted and...

Monitoring the behavior of potential output helps policymakers implement appropriate policies in response to an economic crisis. In the short-run, estimates of the output gap will guide the timing of implementation and withdrawal of stimulus measures. In the medium- to long-term, these estimates...