The Network Structure of Money Multiplier

Abstract

The money view of banking emphasizes deposits as part of money supply that central banks can manage to influence the macroeconomy (Friedman and Schwartz, 1963). The credit view focuses instead on the asset side of bank balance sheets and proposes a bank lending channel (Bernanke, 1983). In this paper, we show that the monetary role of deposits is in fact key to the credit channel as it connects monetary base and bank lending. As deposits circulate as means of payment, settlement reshuffles liquidity (reserves) among banks. The network topology of such reserve flows determines banks' exposure to liquidity risk and their willingness to invest in illiquid loans. We develop a model to capture this mechanism. Our structural estimation explores transaction-level data and characterizes a money multiplier that emerges from the liquidity percolation in payment system. Payment network generates liquidity externalities of banks' lending decisions and amplifies the volatility of credit supply. A small set of banks are critically positioned in the network and contribute disproportionately to the credit cycle.

Keywords: Credit supply, inside money, payment, network, externalities, systemic risk

JEL Classification: E42, E43, E44, E51, E52, G21, G28