| Abstract: | This paper asks how market shares should be computed for analysis of a consummated merger. It is argued that pre-merger market shares adjusted for the direct effects of the merger should be used. The actual post merger market shares (which are available only for consummated mergers) should not form the basis of an analysis of the competitive effects of the merger because they may reflect confounding factors, such as entry, exit, or a change in capacity of third-party rivals, unrelated to the merger. |
