This paper develops a set of approximate band-pass filters designed for use in a wide range of economic applications. In particular, we design and implement a specific band-pass filter which isolates business-cycle fluctuations in macroeconomic time series. This filter was designed to isolate...

Recent developments in macroeconomic theory emphasize that transient economic fluctuations can arise as responses to changes in long run factors -- in particular, technological improvements -- rather than short run factors. This contrasts with the view that short run fluctuations and shifts in...