In a recent paper, Fajardo et al. (2009) propose an alternative semiparametric estimator of the fractional parameter in ARFIMA models which is robust to the presence of additive outliers. The results are very interesting, however, they use samples of 300 or 800 observations which are rarely...

Perron and Rodríguez (2003) claimed that their procedure to detect for additive outliers (Tau-d) is powerful even when we have departures from the unit root case. In this note, we use Monte-Carlo simulations to show that Tau-d is powerful when we have ARFIMA(p; d; q) errors. Using simulations,...

This note analyzes the empirical size of the augmented Dickey and Fuller (ADF) statistic proposed by Perron and Rodríguez (2003) when the errors are frac- tional. This ADF is based on a searching procedure for additive outliers based on …rst-differences of the data named Tau- d. Simulations...