EMPIRICAL EVIDENCE ON FTC ENFORCEMENT OF THE MERGER GUIDELINES.

The Justice Department's 1982/1984 merger guidelines identify various factors--concentration, entry barriers, ease of collusion, efficiency--that would thereafter determine whether the government will challenge a merger. Analysts have criticized enforcement agencies, however, for not following the guidelines, and criticize the guidelines themselves for not identifying the weights attached to the factors. Using a 1982-86 sample of seventy horizontal mergers, we examine which factors influenced Federal Trade Commission decisions to challenge mergers. The relative importance of the guidelines and other factors in merger challenges is measured, and related empirical issues are also explored. [ABSTRACT FROM AUTHOR]