Financial markets are abuzz with the possibility of a Microsoft-Yahoo merger or a Google-Yahoo to block it. A heavy dose of the chatter is consumed by the regulatory implications of either: will the antitrust agencies in the US and European Union approve the transaction? The deals pivot on such anticipations. Of course, antitrust laws are meant to encourage efficient mergers and disrupt the rest. But that careful delineation proves a challenge. Full article available at ft.com. http://www.ft.com/cms/s/0/3592fa90-2b43-11dd-a7fc-000077b07658.html. Also available by [PDF Download] on Prof. Hazlett’s faculty profile.