Point taken - I had simply assumed that "dummify x" and "dummify(x)" did the same thing and that they were provided for use in different circumstances. In particular, it is much easier to use dummify(x) in a function because it creates a list automatically without needing to know anything about the number of categories or variable name. Would it be possible to extend the specification of the function? The syntax that I have in mind is: dummify(x,n) where (a) n=0 means no categories are dropped, (b) n=1 means that the first category is dropped (default), and (c) n=2 means that the last category is dropped. Then, dummify(x) would be a synonym for dummify(x,1). Irrespective of whether the command "dummify x" or the function "dummify(x)" is used, the operation still results in the creation of dummies for all panel units rather than just those present in x. Gordon