Aggregate Concentration, Market Size and EU Integration: Evidence from Southeast Europe

This paper has two purposes: first, to map aggregate concentration, that is to estimate economic concentration among the largest companies, in the economies of Southeast Europe, and second, to assess how is the level of aggregate concentration related to market size, international trade and integration to the European Union. Based on company data from ten countries two types of concentration indices are computed – concentration ratio and Gini coefficient. The results suggest that aggregate concentration among the examined countries varies considerably. Although correlated, both measures of concentration seem to measure different aspects of economic concentration. Both measures decline with domestic market size, measured by country's population. Foreign market size, measured as exports, seems to be positively associated with the concentration ratio, but not with the disparity among large companies. In addition, EU integration does not seem to have a significant effect on aggregate concentration at least for the sample at hand.