Key points are not available for this paper at this time.
Joseph P. Hughes, William Lang, Loretta J. Mester, Choon-Geol Moon, Efficient Banking under Interstate Branching, Journal of Money, Credit and Banking, Vol. 28, No. 4, Part 2: Payment Systems Research and Public Policy Risk, Efficiency, and Innovation (Nov., 1996), pp. 1045-1071
Hughes et al. (Fri,) studied this question.