a market structure-performance analysis, together with the weight accorded to them, tends to vary widely according to the predilections of the researcher.
The stated reasons for including one or more of these additional variables in the industry concentration equation tend to vary according to the particular researcher, and according to the specific industry or economy on which the research is focused. The underlying reason in all instances of the use of such extraneous variables in industry concentration studies, however, appears to be a desire on the part of the researchers to arrive at a different conclusion than that which would be drawn from unadulterated concentration research. In all studies where explanatory or modifying variables are cited in market structure-performance analysis studies, the conclusion is either that (1) concentration does not actually exist, although it appears to exist when the added variable is removed, or (2) although concentrati
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