Abstract:
The "ideal" band-pass filter can be used to isolate the component of a time series that lies within a particular band of frequencies, but applying this filter requires a data set of infinite length. In practice, some sort of approximation is needed. Using projections, the authors derive approximations that are optimal when the time-series representations underlying the raw data have a unit root, or are stationary about a trend.
Related works: Working Paper: The Band Pass Filter (1999) Journal Article: The Band Pass Filter (2003) This item may be available elsewhere in EconPapers: Search for items with the same title.