The CSSM Procedure

The OBSINDEX statement specifies a numeric input data variable that, together with the ID variable, uniquely identifies the observations within a BY group. This statement is essential for the reproducibility of the computations in situations where there can be multiple observations in a given BY group that have the same ID value. These types of situations arise when you are analyzing panels of time series or when the data are longitudinal. For examples of using this statement, see the section Getting Started: CSSM Procedure, Example 13.7, Example 13.9, and Example 13.11.