does sas require stationary regression is proc ucm stationary what is the proc ucm used for do a dependent have to be stationar when ssa ucm is used what is stationarity do you need stationary data before using proc ucm? which model would be used to isolate the seasonality and seasonal component in a data series? why is proc ucm used is proc ucm stationar what is proc ucm does proc ucm depend on observability what is proc ucm what is proc ucm why do we need stationarity in sas what is proc ucm does a dependent have to be stationarily treated what is proc ucm why does proc ucm need to be stationar is proc ucm stationary? a. sas bs is proc ucm stationary