During her remarks updating the Department of Justice/Federal Trade Commission joint review of the Horizontal Merger Guidelines, Assistant Attorney General Christine Varney noted a few areas where updating the Guidelines “appears worthwhile.”1
Implicit in deemphasizing the sequential nature of the Guidelines inquiry is a recognition that defining markets and measuring market shares may not always be the most effective starting point for many types of merger reviews. Remember, the purpose of defining a market and assessing shares is to assess potential harm. When it is clear, for instance, that either certain vulnerable customers are likely to be harmed by a merger, or that certain customers have in fact been harmed by a consummated merger, the need to define a market to assess likely competitive effects is diminished.2
