Correspondent services and cost economies in commercial banking

Prior bank cost function studies have ignored the fact that some banks obtain a substantial amount of services from their correspondents. If these services are paid for with compensating deposit balances, their cost to the purchasing bank is not reflected in standard expense reports. This paper investigates whether explicit consideration of theese correspondent costs materially affects estimated bank returns to scale. The results indicate that the level of banksoperating costs is underreported by as much as 15%. While scale economy estimates for unit banks are not significantly affected by the addition of correspondent service costs, prior studies have overestimated branch bank scale economies by a small but statistically significant amount.