Research uncovers interbank market frictions, policy implications
Federal Reserve researchers published a paper analyzing demand and supply for central bank reserves in an ample-reserves framework. The study highlights distributional frictions in the federal funds market that emerge before aggregate reserves become scarce.
Lender heterogeneity shapes reserve dynamics
The paper recovers information by isolating the small interbank segment of the federal funds market.
Using high-frequency bank-level data, the authors employ deposit shocks as an instrument for bank borrowing demand.
Their analysis reveals that non-bank lenders, such as Federal Home Loan Banks (FHLBs), supply funds elastically, consistent with pure arbitrage behavior.
In contrast, bank lenders exhibit price inelasticity, which intensifies as their reserve balances decline, particularly for specialized 'bankers' banks'.
This interbank segment highlights distributional frictions in the federal funds market that emerge well before aggregate reserves become scarce.
The findings underscore the importance of accounting for lender heterogeneity for inferring bank liquidity conditions and provide new evidence on monetary policy transmission in an ample-reserves regime.
The study challenges the representative-bank framework by demonstrating that aggregating across different types of market participants confounds identification and the information content of fed funds rates.
Ample reserves, muted signals
The Federal Reserve's adoption of an ample-reserves framework in 2019 significantly shifted monetary policy implementation, relying on administered rates like Interest on Reserve Balances (IORB) and the Overnight Reverse Repo Facility (ON RRP).
A key consequence of this framework is the atrophy of traditional interbank markets, as banks no longer rely on unsecured borrowing to manage liquidity.
This environment mutes the classic real-time barometer of bank health, making it harder to observe interbank rates precisely when cross-sectional liquidity tightens.
The paper argues that existing aggregate reserve demand models, which identify a 'kink' as the onset of scarcity, are ill-suited because they overlook systematic heterogeneity among market participants, blending arbitrage-motivated activity with genuine liquidity demand and supply.
Distributional frictions, not aggregate scarcity
The paper fundamentally redefines reserve scarcity, shifting focus from aggregate levels to critical distributional frictions within the interbank market.
This nuanced understanding is vital for the Federal Reserve, enabling it to distinguish between broader market strains and genuine bank liquidity tightness.
Consequently, these findings offer a more precise lens for safeguarding financial stability and ensuring effective monetary policy transmission.