In this note, we highlight a minor error in the asymptotic distribution of one of the Busetti and Harvey (2001) tests for stationarity in the presence of structural breaks, and provide corrected asymptotic critical values where relevant. In addition, we examine the extent to which finite sample...

Trends are extracted from the central England temperature (CET) data available from 1723, using both annual and seasonal averages. Attention is focused on fitting non-parametric trends and it is found that, while there is no compelling evidence of a trend increase in the CET, there have been...

We consider tests of the null hypothesis of stationarity against a unit root alternative, when the series is subject to structural change at an unknown point in time. Three extant tests are reviewed which allow for an endogenously determined instantaneous structural break, and a related fourth...

Techniques for testing the null hypothesis of difference stationarity against stationarity around some deterministic function have received much attention. In particular, unit root tests where the alternative is stationarity around a smooth transition in a linear trend have recently been...

Systems of economic data potentially exhibit a number of common features, which aid both econometric modelling and economic interpretation. This paper surveys a variety of common features and applies the corresponding testing and estimation techniques to systems of macroeconomic time series in...

A desirable property of a forecast is that it encompasses competing predictions, in the sense that the accuracy of the preferred forecast cannot be improved through linear combination with a rival prediction. In this paper, we investigate the impact of the uncertainty associated with estimating...

In practice a degree of uncertainty will always exist concerning what specification to adopt for the deterministic trend function when running unit root tests. While most macroeconomic time series appear to display an underlying trend, it is often far from clear whether this component is best...

We analyze the impact of nonstationary volatility on the break fraction estimator and associated trend break unit root tests of Harris, Harvey, Leybourne, and Taylor (2009) (HHLT). We show that although HHLT’s break fraction estimator retains the same large-sample properties as demonstrated by...