Abstract:
The method proposed in this chapter is making use of the bispectrum transformation to estimate the level of integration of a fractionally integrated time series. Bispectrum ransformation transforms the series into a two dimensional frequency space, and thus has higher information content compared to the Geweke-Porter-Hudak method. The bispectrum method is an alternative to the recently proposed wavelet method that transforms the original series into time-frequency (or time-scale) space.