Editorials Will they ever learn? January 27, 2014 Share 1 -- If you thought that after Delta/Northwest, United/Continental and Southwest/AirTran the airlines have made and learned from every merger-related mistake that could be made, you'd be wrong. We recently reported that American and US Airways started sharing codes but without sharing pricing information. As a result, as some startled observers discovered a fortnight ago, it appeared that the two airline brands were still engaged in price competition against each other, with seats coded US selling for a lot less than seats on the same flight coded as AA. This lingering price war might please the Justice Department, but it's not much of a confidence-builder for the airlines' passengers or travel agents. It is true, as the carriers noted, that different prices often prevail on codeshare flights. But American and US Airways are not engaged in some arm's-length interlining here. They are merger partners, and they should have anticipated this and prevented it. Let's hope they take this as a cautionary tale to be very certain that, before they pull integration triggers, they're not shooting themselves in the foot.