Seasonal adjustment usually relies on statistical models of seasonality that treat seasonal fluctuations as noise corrupting the `true' data. But seasonality in economic series often stems from economic behavior such as Christmas-time spending. Such economic seasonality invalidates the...

For model-based seasonal adjustment, there are explicit formulas for obtaining the variance of the seasonal factors or the seasonally adjusted series. For series adjusted with X-11 or X-12, variance estimates are generally based on a linear approximation of the seasonal adjustment procedure. The...

This paper describes the finished goods inventory behavior of more than 700 U.S. manufacturing firms between 1985-93 using a new Census Bureau longitudinal data base. Three key results emerge. First, there is a broad mix of production-smoothing and production-bunching firms, with about...