Payments systems, liquidity, collateral, and central banking

A monetary model is constructed to explore the risk-sharing role of gross settlement as a determinant of money demand for consumption in a credit economy. Due to a deferred payment system, the costs of gross and net settlement are sensitive to the nominal interest rate. Gross settlement may dampen a consumption loss against interest-rate risk arising from inflation by acquiring additional cash from a financial market. Hence, it is optimal for the government to influence inflation and to drive net settlement out of a payment system. For payment policy, the optimal collateral requirement ratio is one whereas for monetary policy the optimal money growth rate is infinity. Payment policy can be a useful alternative to monetary policy.