The `ideal' band pass filter can be used to isolate the component of a time series that lies within a particular band of frequencies. However, applying this filter requires a dataset of infinite length. In practice, some sort of approximation is needed. Using projections, we derive...

We characterize the change in the nature of the money growth-inflation and unemployment-inflation relationships between the first and second halves of the 20th century. The changes are substantial, and we discuss some of the implications for modeling inflation dynamics. We stress the...

The `ideal' band pass filter can be used to isolate the component of a time series that lies within a particular band of frequencies. However, applying this filter requires a dataset of infinite length. In practice, some sort of approximation is needed. Using projections, we derive...