Efficient Horizontal Mergers.

This paper considers the Debreu [6] - Farell [10] - Fdre [7] measure of efficiency of merger to compare economic efficiencies of alternative merged entities in a homogenous good industry. The comparability results rely on concentration curve dominance relation and identify the class of cost functions for which efficiency ranking the entities becomes unambiguous. The results have been developed under alternative assumptions about the total output and number of firms of the merging subgroups.