Before the era of large central bank balance sheets, banks relied on incoming payments to fund outgoing payments in order to conserve scarce liquidity. Even in the era of large central bank balance sheets, rather than funding payments with abundant reserve balances, we show that outgoing payments remain highly sensitive to incoming payments. By providing a window on liquidity constraints revealed by payment behavior, our results shed light on thresholds for the adequacy of reserve balances. Our findings are timely, given the ongoing shrinking of central bank balance sheets around the world in response to inflation.

Key words: real-time gross settlement (RTGS) systems, quantitative tightening, balance sheet management, reserve balances