The two principal reasons that the 1992 Horizontal Merger Guidelines achieved longevity, judicial acceptance, and international imitation were: (1) for the most part, it asked the right questions; and (2) it provided a structured framework in which to ask those questions. If those attributes of the 1992 Guidelines are viewed as evaluative criteria against which to judge any revisions, the 2010 Horizontal Merger Guidelines are a mixed bag.
The revised Guidelines evidence a decided move away from asking the "right" questions, substituting for those questions a greater exposition on the direction of antitrust merger analysis, the general principles underlying it, and some of the tools that might be employed in conducting that analysis. The additional exposition adds explanatory power at a general level but probably spells an earlier obsolescence for the final document. Predictions of the demise of the structured framework appear to have been premature. The framework remains largely intact even while the Agencies attempt to side-step the statutory requirement of market definition.