DESCRIPTION: The Department of Justice and Federal Trade Commission are proposing to update their enforcement guidelines for assessing vertical mergers under the antitrust laws. These are mergers that combine two companies that operate at different levels in a supply and marketing chain, and therefore do, or could, do business with each other. These guidelines would replace guidelines published in 1984, before the arrival of the internet and its dramatic transformation of the marketplace. Our comments explain that the draft guidelines need more work, and urge the agencies to make sure the final guidelines speak to the competition problems in today’s online marketplace, and that they are written so they can be understood by the wider public that is increasingly aware of and concerned about these problems.