The PICKMDL statement. The PICKMDL statement causes the X12 procedure to automatically select a regARIMA model from a list of candidate models defined by the user in the MDLINFOIN= data set. The METHOD= option in the PICKMDL statement controls how the model selection is performed. The selected regARIMA model then extends the time series prior to performing the X-12-ARIMA seasonal adjustment. The PICKMDL statement is experimental for this release.

The SEATSDECOMP statement. The SEATSDECOMP statement first computes the B1 series by using the X-12-ARIMA method and then performs a seasonal adjustment of the B1 series by using the SEATS decomposition method. SEATS is a polynomial-based seasonal decomposition method developed by Gómez and Maravall (1997a, 1997b). You can write the resulting components to a data set by specifying the OUT= option in the SEATSDECOMP statement. The SEATSDECOMP statement is experimental in this release.

The NOAPPLY option has been added as a general option to the REGRESSION statement. The NOAPPLY option specifies whether specific regression effects are to be included in the B1 series that is seasonally adjusted.

The AICTEST option has been added as a general option to the REGRESSION statement. The AICTEST option enables you to specify a regression effect, but the effect is not included in the regARIMA model unless the results of an AIC test determine that the effect should be included in the model. Thus, the AICTEST option can be used to automatically select regressors for the regARIMA model.