ABSTRACT
First, no one would deny the need for periodic revision of the class location of occupations: time-proof social classifications have not yet been invented. 1 However, some care is needed in singling out the occupations to be relocated. Let us take an example in which criterion Z assigns occupations L1 and L2 to a given class under the common label L. If conditions in L2, but not in L1, then worsen in time, a straightforward aggregation problem arises. 2
