The aim of this paper is to study the changes in market concentration in the Brazilian mining and manufacturing industries that took place from 1996 to 2003. The paper decomposes the Herfindahl-Hirschman index into variations in the size distribution and the number of firms. The results show that the average concentration did not change greatly in the period analyzed; however, a small group of industries showed significant differences in concentration. In these cases, changes in size distribution appear to have more importance than changes in the number of firms.
Market concentration; Brazilian industry; Herfindahl-Hirschman index; Brazil; Decomposition
