In this article we provide evidence for a rational bubble in S\&P 500 stock prices by applying a test for changing persistence under fractional integration proposed by Sibbertsen and Kruse (2007). We find strong evidence for stationary long memory before the estimated change point in 1955 and a...

This paper proposes a new unit root test against a non-linear exponential smooth transition autoregressive (ESTAR) model. The new test is build upon the non-standard testing approach of Abadir and Distaso (2007) who introduce a class of modified statistics for testing joint hypotheses when one...

We consider the problem of forecasting time series with long memory when the memory parameter is subject to a structural break. By means of a large-scale Monte Carlo study we show that ignoring such a change in persistence leads to substantially reduced forecasting precision. The strength of...

This research points to the serious problem of potentially misspecified alternative hypotheses when testing for unit roots in real exchange rates. We apply a popular unit root test against nonlinear ESTAR and develop a Markov Switching unit root test. The empirical power of these tests against...

In this paper we analyze the convergence of interest rates in the European MonetarySystem (EMS) in a framework of changing persistence. This allows us to estimate the exact date of full convergence from the data. A change in persistence means that a time series switches from stationarity to...

We consider the problem of forecasting time series with long memory when the memory parameter is subject to a structural break. By means of a large-scale Monte Carlo study we show that ignoring such a change in persistence leads to substantially reduced forecasting precision. The strength of...