The PANEL Procedure

BY Statement

BY variables ;

A BY statement obtains separate analyses on observations in groups that are defined by the BY variables. When a BY statement appears, the input data set must be sorted both by the BY variables and by cross section and time period within the BY groups.

The following statements show an example:

   proc sort data=a;
      by byvar1 byvar2 csid tsid;

   proc panel data=a;
      by byvar1 byvar2;
      id csid tsid;