The corrections provided by Xie and Cui [Xie, F., Cui, W., in press. Cost range and network structures. Social Networks, 30] to one of the theorems provided by Doreian [Doreian, P., 2006. Actor network utilities and network evolution. Social Networks, 28, 137-164] are both necessary and helpful. Accepting these corrections, and linking them more closely to the work of Hummon [Hummon, N.P., 2000. Utility and dynamic social networks. Social Networks, 22, 221-249], leads to some additional suggestions which, together with a restatement of some earlier results, help set the foundations for future work in this area. (C) 2007 Elsevier B.V. All rights reserved.