Hi Brian,
as the help states, this is currently only supported for OLS. I think 
the reason is simply, that this has not been implemented, yet.
But you may want to have a look at my "fcnaive" package which also 
supports for some specific ("naive") ARIMA-variants recursive forecasting.
<>
pkg install naiveFC
help naiveFC
</>
Artur
Am 23.11.24 um 18:02 schrieb Brian Revell:
> Is there any reason why recursive forecasts cannot be included in the 
> ARIMA option for univariate modelling together with their confidence 
> intervals when the model is truly univariate with no exogenous varisbles 
> included in the specification  Clearly post sample data the MA terms 
> would drop out of the forecasts that would effectively only require the 
> AR parameters and any differencing.
> 
> Brian