Group Dummy Variables
In our last example, we consider the use of the @INGRP pool function to estimate an specification containing group dummy variables (see "Pool Series"). Suppose we modify our pool definition so that we have defined a group named "MYGROUP" containing the identifiers "GE", "GM", and "GY". We may then estimate a pool specification using the common regressor list:

c f? k? @ingrp(mygrp)