Banks as Liquidity Multipliers

We characterize the interaction between banks’ liquid assets purchases and deposit issuance decisions. Using global games, we derive a liquidity multiplier: the amount of deposits a bank can create when endowed with one additional unit of liquid asset to maintain a given level of liquidity risk. In our central theorem, we prove it is larger than unity. This entails that banks have a special role in enhancing liquidity provision, “multiplying” liquid assets into a larger quantity of deposits. Our theory has implications for banks’ balance sheet choices, the pricing of liquid securities, and the role of public liquidity provision.