Recall that most SAS/ETS procedures expect input data to be in the standard form, with no omitted observations in the sequence of time periods. When data are missing for a time period, the data set ...

This example creates and prints an output data set that shows the differences between matching observations. In Comparing Observations with an ID Variable, the output does not show the differences ...

This is a preview. Log in through your library . Abstract The omission of important variables is a well-known model specification issue in regression analysis and mixed linear models. The author ...