Branching, scale economies, and banking costs

Abstract

In this paper, we develop and estimate a model of bank costs based on a theory of the branch cost function. First, we show that convenient branch location is important to banking customers and implies that banks do not necessarily operate branches at minimum average cost. This theoretical result provides a rationale for including branch variables in the bank cost function. Second, we estimate a statistical cost equation derived explicitly from assumptions about the branch cost function and including branch output variables. Our empirical results suggest substantial economies of scale at the branch level, but no economies from expansion by branching. Finally, we show that the resulting cost structure of the banking industry does not imply that a highly concentrated banking structure is necessary for efficiency. Thus, economies of scale would not be expected to force small banks out of the market, even if current restrictions on interstate banking are liberalized.