Research Discussion Paper – RDP 2024-08 Modelling Reserve Demand with Deposits and the Cost of Collateral

The RBA controls short-term interest rates by offering to lend as many reserves as banks demand at a rate close to its target for monetary policy. At this rate, banks' demand drives the amount of reserves the RBA supplies and subsequently the size of its balance sheet. I estimate a substantial increase in Australian banks' reserve demand since the COVID-19 pandemic. I find an increase in banking system deposits explains a large part of the increase in reserve demand through an associated shift to the right in Australian banks' reserve demand curve. The link between deposits and reserve demand suggests banks are willing to pay for the convenience of holding additional reserves to manage payments between depositors, or that banks hold reserves against deposits as a precaution in case of liquidity stress. The value of collateral also shifts banks' reserve demand curve as it changes the price at which banks can fund reserves through the repo market. The role of collateral in explaining the increase in banks' reserve demand is likely small as its value is little changed since the pandemic.