UCM Procedure
Modeling an Autoregression
An autoregression of order one can be thought of as a special case of a cycle when the frequency is either 0 or
. Modeling this special case separately helps interpretation and parameter estimation. The autoregression component
is modeled as
where . An autoregression can also provide an alternative to the IRREGULAR component when the model errors show some autocorrelation. You can incorporate an autoregression in your model by using the AUTOREG statement.
Last updated: July 09, 2026