What does the 30 series limit in a Transfer Function mean?
A transfer function is simply a more powerful version of an ordinary multiple regression. When we talk about 30 series in a mode , we mean at most 29 inputs. If you start with a univariate model then AUTOBOX will at most be able to include 29 dummy or intervention series in its augmentation process. Essentially the identification of intervention variables leads to a multiple series model. The inclusion of causal variables and interventions can quickly deplete the 29 open positions.
