Payments systems and monetary policy

A dynamic spatial model is constructed where there is a role for money and for centralized payments arrangements, and where there are aggregate fluctuations driven by fluctuations in aggregate productivity. With decentralized monetary exchange and no centralized payments arrangements, there is price level indeterminacy, and the equilibrium allocation is inefficient. A private clearinghouse arrangement improves efficiency but produces a real indeterminacy. The pricing of daylight overdrafts is irrelevant for the equilibrium allocation. Efficiency is achieved with a zero nominal interest rate on overnight central bank lending, or through private overnight interbank lending.