We study the empirical behaviour of semi-parametric estimation for long-memory models when the true data generating process exhibits a change in persistence. Evidence for long memory is likely to be found. Procedures for discrimination between different models are proposed.

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...

We extend the monitoring of structural breaks in classic cointegration proposed by Wagner and Wied (2017) to explicitly allow for fractional cointegration and breaks in these fractional relations with possible deterministic trends. To estimate the parameters we use a fully modified OLS estimator...