WARNING: Improper Use of the New Horizontal Merger Guidelines Can Result in Overly Narrow Markets, Mistaken Inferences of Market Power, and Wrong-Headed Analyses

Every first-year law student has heard the story of the man who was mowing his lawn when he realized that his hedge also needed trimming.  Since he didn’t own a hedge trimmer, he lifted the lawnmower up, turned it on its side, and then accidentally cut off his fingers.  He sued the manufacturer, claiming that the label should have warned him not to trim his hedge with a lawnmower.

With all of the tools in the new Guidelines-natura