Size and Scale Economies in Japanese Cooperative Banking

This paper examines the relationship between size and scale economies of cooperative banks in Japan (namely Shinkin and credit cooperatives). We use the translog cost-function methodology and intermediation approach coupled with a large set of both cross-sectional and panel data over the period 2003 to 2006. We find significant diseconomies of scale for both the full sample and sub-samples of small and large cooperative banks. It is of interest to note that larger cooperative banks were at cost disadvantage as compared to small ones throughout most of the period. Thus, bigger is not always better, at least in cost terms