Over-all Concentration, Conglomerate Bigness and the Largest European Corporations

It has often been stated that the absolute size of a firm is irrelevant to the question of competition and that there is no or little connection between the aggregate level of concentration and the level of concentration in individual markets; and while concentration ratios within particular industries are accepted as conventional indicators of market power, the use of measures of over-all concentration has been viewed with suspicion. Over-all (or aggregate) concentration is defined as being the proportion of some aggregate of economic activity accounted for by a relatively small number of the largest firms taken together.