level shifts in arima models level shift in arima model which level shift is an exogenous when is level shift of arima when does an arima level shift occur what is level shift in arima when is level shift used how often do you enter shifts what is level shift analysis in arima when is level shift what is level shift in arima what is level shift in arima why not enter level shifts which level shift in arima model? what level shift is ls 2010 which level of shift is used in the arima model when is level shift used in arima how to enter level shifts in arima what level shifts do i have for arima how to use arima level shift analysis