中央银行储备的需求与供给故事

Federal Reserve Board, Washington, D.C.ISSN 1936-2854 (Print)ISSN 2767-3898 (Online) A Tale of Demand and Supply for Central Bank Reserves Sriya Anbil, Sebastian Infante, Zeynep Senyuz Please cite this paper as:Anbil,Sriya,Sebastian Infante,and Zeynep Senyuz(2026).“ATale of DemandandSupply for Central Bank Reserves,”Finance and Economics Discussion Se-ries2026-028.Washington:Boardof Governors of the Federal Reserve System,https://doi.org/10.17016/FEDS.2026.028. NOTE: Staff working papers in the Finance and Economics Discussion Series (FEDS) are preliminarymaterials circulated to stimulate discussion and critical comment.The analysis and conclusions set forthare those of the authors and do not indicate concurrence by other members of the research staff or the A Tale of Demand and Supply for Sriya Anbil†Sebastian Infante‡February 2026 Abstract In an ample-reserves framework, administered rates anchor money markets but sup-press information from unsecured interbank trading. We recover that information byisolating the small interbank segment of the federal funds market. Using high-frequencybank-level data, we employ deposit shocks as an instrument for bank borrowing de-mand. Our analysis reveals that non-bank lenders, such as Federal Home Loan Banks,supply funds elastically, whereas bank lenders exhibit price inelasticity, which intensi- Keywords:monetary policy implementation, balance sheet policy, central bank re- 1Introduction The Federal Reserve’s (Fed) monetary policy implementation framework underwent a sig-nificant shift following the policy response to the Global Financial Crisis (GFC) and theofficial adoption of an ample-reserves regime in 2019.In this framework, the Fed steers money market rates into the target range by setting administered rates on its liabilities,primarily the interest on reserve balances (IORB) and the overnight reverse repo facility(ON RRP).1IORB is the main policy tool for rate control and conceptually operates by de- A consequence of the ample-reserves framework is the atrophy of interbank markets.By greatly increasing the amount of reserves in the system, banks have not had to rely onunsecured interbank borrowing and lending in the federal funds market (fed funds) to managetheir liquidity. In this environment, the lion share of trading reflects arbitrage opportunitiesbetween participants that do and do not receive IORB. Therefore, short-term money marketrates often trade well below IORB, suggesting that it is a poor measure of banks’ trueopportunity cost of lending to one another. Most trading in the federal funds market thus Our contribution is twofold.First, we show that intermediaries who lend in fed fundsmarket shape what the data say about reserve conditions. When trades are dominated bynonbank lenders—most notably FHLBs that price elastically to capture the spread between their liquidity.By contrast, bank lenders’ volume-weighted rates co-move with aggregatereserves and with the lenders’ own reserve positions. These facts underscore the importanceof accounting for lender heterogeneity for inferring bank liquidity conditions.Second, we Much of the literature devoted to understanding at what point reserves transition from“abundant” to “ample” levels involves the estimation of an aggregate reserve demand curveand identifying the“kink” as the onset of reserve scarcity (Lopez-Salido & Vissing-Jorgensen(2023), Afonso et al. (2022), Acharya & Rajan (2024)).By regressing daily changes inEFFR relative to IORB on fluctuations in aggregate reserves and deposits, they trace a two-regime relationship that is essentially flat when reserves exceed a threshold and steepens Our approach is motivated by two stylized facts. First, lender composition in fed funds isheterogeneous: nonbanks (FHLBs), who do not earn IORB on their reserve balances, supplythe majority of fed funds to earn the spread between EFFR and IORB (Anderson et al.2021).FHLBs mainly lend to foreign banks, that are subject to less stringent regulationsrelative to domestic banks, and thus have a greater willingness to expand their balancesheet to earn the spread between EFFR and IORB to capture arbitrage.Bank lenders,in contrast, lend subject to their own reserve positions and liquidity needs of their other The structure of the fed funds market poses challenges for measuring bank liquidityconditions. When transactions in the fed funds market are dominated by nonbank lending,slopes estimated on the EFFR primarily nonbanks’ incentives to supply reserves to profit from arbitrage spreads, not a tightening in banks’ reserve management.Conversely, theinterbank rate between bank borrowers and lenders moves in response to their funding needsand their willingness to deploy those funds relative earning IORB, yielding a cleaner signal In this paper, we rely on micro data to disentangle these two distinct drivers of fedfunds trading activity.Specifically, we estimate thesupply elasticityof lenders in the fed funds ma