Merger policy in the Obama administration

Have gone the last week without my laptop.  Try it sometime; highly recommended. 

Just as NC State was shutting down for the holidays, AT&T decided to give up its bid for T-Mobile USA, presumably because it decided the odds of approval were low.  (Disclaimer: I do have a modest personal stake in this, having bought an iPhone from AT&T at a time when they provided unlimited domestic data for $30/month.  I was hoping that the extra bandwidth obtained from T-Mobile would result in better service.)  WSJ produced a good post mortem that discerned a pattern in the Obama administration's merger policy: mergers between firms competing in the same line of business (called horizontal mergers) are being frowned upon whereas mergers between firms in different stages of the same value chain (called vertical mergers) seem to be ok.  Recent examples of vertical mergers that have been approved include Comcast and NBC Universal and Ticketmaster's hookup with Live Nation. 

It will be interesting to see how tight a standard the current Department of Justice will apply.  Will we go back to the days of the infamous 1966 Von's Grocery decision, which zapped a merger between Von's and Shopping Bag because they would have had an eight percent combined market share in the LA metro area?