| Seasonal Adjustment |
The X11 procedure provides seasonal adjustment of time series by using the Census X-11 or X-11 ARIMA method. The X11 procedure is based on the U.S. Bureau of the Census X-11 seasonal adjustment program and also supports the X-11 ARIMA method developed by Statistics Canada. The X11 procedure includes the following features:
decomposition of monthly or quarterly series into seasonal, trend, trading day, and irregular components
both multiplicative and additive form of the decomposition
all the features of the Census Bureau program
support of the X-11 ARIMA method
support of sliding spans analysis
processing of any number of variables at once with no maximum length for a series
computation of tests for stable, moving, and combined seasonality
optional printing or storing in SAS data sets of the individual X11 tables that show the various components at different stages of the computation; full control over what is printed or output
ability to project seasonal component one year ahead, which enables reintroduction of seasonal factors for an extrapolated series
The X12 procedure provides seasonal adjustment of time series using the X-12 ARIMA method. The X12 procedure is based on the U.S. Bureau of the Census X-12 ARIMA seasonal adjustment program (version 0.3). It also supports the X-11 ARIMA method developed by Statistics Canada and the previous X-11 method of the U.S. Census Bureau. The X12 procedure includes the following features:
decomposition of monthly or quarterly series into seasonal, trend, trading day, and irregular components
support of multiplicative, additive, pseudo-additive, and log additive forms of decomposition
support of the X-12 ARIMA method
support of regARIMA modeling
automatic identification of outliers
support of TRAMO-based automatic model selection
use of regressors to process missing values within the span of the series
processing of any number of variables at once with no maximum length for a series
computation of tests for stable, moving, and combined seasonality
spectral analysis of original, seasonally adjusted, and irregular series
optional printing or storing in a SAS data set of the individual X11 tables that show the various components at different stages of the decomposition; full control over what is printed or output
optional projection of seasonal component one year ahead, which enables reintroduction of seasonal factors for an extrapolated series