Andem - 2:14 am on Nov 17, 2011 (gmt 0)
If you paid for the content, then there's no reason why you shouldn't take credit for it. Unless you have some kind of agreement with the actual author which prohibits you from taking credit. Either way, don't give an author markup to the author unless a) he has a G+ profile with more than an acceptable amount of followers (ie. more than you), and he will accept the work as his own;
If you don't want your competitors stealing your writers, I would definitely not make their information public. In fact, if I was a competitor, the first thing I would look for is who was writing for you.
My advice: don't do it. Mark it up with your own details or don't do it at all.