We examine some of the consequences on commonly used unit root tests when the underlying series is integrated of order two rather than of order one. It turns out that standard augmented Dickey-Fuller type of tests for a single unit root have excessive density in the explosive region of the...

Frequently, seasonal and non-seasonal data (especially macro time series) are observed with noise. For instance, the time series can have irregular abrupt changes and interruptions following as a result of additive or temporary change outliers caused by external circumstances which are...

This paper introduces a representation of an integrated vector time series in which the coefficient of multiple correlation computed from the long-run covariance matrix of the innovation sequences is a primitive parameter of the model. Based on this representation, we propose a notion of near...

Long-horizon interest rates in the major international bond markets fell sharply during 2004 and 2005, at the same time as US policy rates were rising; a phenomenon famously described as a 'conundrum' by Alan Greenspan the Federal Reserve Chairman. But it was arguably the decline in...

During 2004 and 2005, long-horizon interest rates fell sharply in major international government bond markets (Greenspan's "conundrum"). This common fall mainly reflected lower long real rates. To investigate possible causes, the authors apply a no-arbitrage affine modeling framework to...

This paper examines the question of whether the ability of market interest rates to predict future policy rate changes in the United Kingdom has changed markedly over the period 1975-2003. Such improvements in predictability could arise from greater transparency in the monetary policy process,...

The purpose of this paper is to characterize three commonly used double unit root tests in terms of their asymptotic local power. To this end, we study a class of nearly doubly integrated processes which in the limit will behave as a weighted integral of a double indexed Ornstein-Uhlenbeck...

We examine some of the consequences on commonly used unit root tests when the underlying series is integrated of order two. It turns out that standard augmented Dickey-Fuller type of tests for a single unit root have excessive density in the explosive region of the distribution. The lower...