Reserve requirements (also called the reserve ratio) are the amount or percentage of customer deposits that a bank must hold in liquid form—either as cash in its vault or as deposits at the central bank—and therefore cannot lend or invest. The requirement is set by the central bank (in the United States, the Federal Reserve) and is intended to ensure banks have enough liquidity to meet normal withdrawals and to help the central bank implement monetary policy.
Key takeaways
– Reserve requirements limit how much of customer deposits a bank may lend: required reserves are unavailable for lending, while excess reserves can be used or invested. (Federal Reserve Board)
– In the U.S., the Federal Reserve sets reserve requirements under the Federal Reserve Act and can change them to expand or contract bank lending. (Federal Reserve Board)
– Following the COVID-19 shock, the Fed set reserve requirements to 0% (effective March 26, 2020) to increase available liquidity. (Federal Reserve)
– Many advanced economies rely more on capital requirements and interest-on-reserves tools than on formal reserve ratios (Canada, UK, New Zealand, Australia and Sweden do not use statutory reserve ratios). (GAO / central bank sources)
How reserve requirements affect banking and the economy
– Liquidity and safety: Required reserves provide a buffer so banks can meet depositor withdrawals, reducing the risk of runs.
– Credit supply (money creation): A lower reserve ratio increases the share of deposits that can be lent, expanding bank credit and the money supply; a higher ratio has the opposite effect.
– Interest rates and monetary stance: Changing reserve requirements is a blunt monetary-policy tool. Increasing the ratio is contractionary (reduces lending, puts upward pressure on interest rates); decreasing it is expansionary. In practice, central banks more often use interest-rate tools and balance-sheet operations than frequent changes to reserve ratios. (Federal Reserve; Federal Reserve Bank)
– Interbank funding and the federal funds market: If a bank lacks required reserves it typically borrows overnight from other banks in the federal funds market or from the central bank discount window; the fed funds rate is a key short-term market rate that influences other interest rates. (Investopedia; Federal Reserve)
Historical evolution — key milestones
– Early 19th century: Banks began holding reserves as protection against withdrawals and to facilitate redeeming banknotes.
– 1863–1865: The National Bank Act imposed a 25% reserve requirement on national banks to promote stability and national currency. (Historical sources)
– 1913: Creation of the Federal Reserve (Federal Reserve Act) established a central lender-of-last-resort and harmonized reserve policy. (Federal Reserve Bank)
– 1917: Initial Federal Reserve reserve bands set at differing percentages for bank types (example: 13%, 10%, 7% for different classes at one point).
– 2006 / 2011: The Financial Services Regulatory Relief Act of 2006 authorized the Fed to pay interest on reserve balances; the Fed started paying interest on reserve balances on Oct. 1, 2011. Paying interest on reserves gave the Fed a new tool to influence short-term rates. (Federal Reserve; Financial Services Regulatory Relief Act)
– March 26, 2020: In response to the COVID‑19 crisis the Federal Reserve reduced reserve requirement ratios to 0% for all deposit tiers to boost liquidity. (Federal Reserve)
Reserve requirements vs. capital requirements
– Reserve requirements (liquidity buffer): Specified liquid assets to be held against deposits so a bank can meet withdrawals and daily payment needs.
– Capital requirements (loss-absorption buffer): Equity and retained earnings that absorb losses on loans and investments, protecting depositors and the financial system.
Both are regulatory constraints but serve different purposes—liquidity vs solvency. Many jurisdictions emphasize capital and liquidity regulation (Basel standards, stress tests, liquidity coverage ratios) rather than large reserve ratios. (Federal Reserve; Federal Reserve Bank of Cleveland)
Example calculation
Assume a bank has $200 million in customer deposits and the reserve requirement is 10%:
– Required reserves = 10% × $200 million = $20 million
– Funds available to lend = $200 million − $20 million = $180 million
If the reserve ratio were lowered to 5%, required reserves would be $10 million and lending capacity would rise to $190 million.
Who sets reserve requirements?
– United States: The Board of Governors of the Federal Reserve sets reserve requirements under authority of the Federal Reserve Act. The Fed also sets the rate paid on reserves and operates other policy tools (interest on excess reserves (IOER), open market operations, standing facilities). (Federal Reserve Board; Federal Reserve)
What a lower or higher reserve requirement means in practice
– Lower reserve requirement:
• Expansionary monetary effect: more funds available for loans, greater credit creation, potential downward pressure on interest rates.
• Banks can convert required cash into loans or investments, increasing liquidity in the broader economy.
– Higher reserve requirement:
• Contractionary monetary effect: fewer funds available for lending, reduced credit supply, upward pressure on interest rates.
• Enhances bank liquidity buffers but reduces capacity to finance consumer and business credit.
Limitations and modern context
– Rarely used frequently: Because changing reserve ratios is a powerful and blunt instrument (it affects all depository institutions immediately), major central banks have tended to rely more on interest-rate policy, paying interest on reserves, open-market operations, and macroprudential capital/liquidity rules. (Federal Reserve; GAO)
– Zero reserve ratio era in the U.S.: With reserve requirements at 0%, the Fed uses IOER, overnight reverse repos, balance-sheet policy, and supervision/regulation to manage liquidity and control short-term rates. (Federal Reserve)
– Differences across countries: Some advanced economies do not maintain statutory reserve ratios and instead regulate liquidity through other tools. (GAO; central bank sources)
Practical steps — for different audiences
For bank treasury and funding managers
1. Maintain contingency funding plans: Identify sources of liquidity (interbank, central bank facilities, liquid asset buffers) and test access under stress scenarios.
2. Optimize balances: With low/no reserve ratios, weigh the ROI of holding central bank balances versus lending or investing; consider operational needs (payments, intraday liquidity).
3. Monitor regulatory changes: Reserve requirements, liquidity coverage ratio (LCR), and other requirements can change; stay ready to adjust funding and asset-liability strategies.
4. Use intra-day liquidity tools and stress tests: Run cash-flow and deposit-run simulations to ensure the bank can meet payments without undue reliance on emergency funding.
For policymakers and central banks
1. Use a toolkit, not just reserve ratios: Combine interest-rate policy, IOER, open-market operations, standing facilities, and macroprudential tools to achieve monetary and financial stability goals.
2. Communicate clearly: If reserve requirements are changed, provide guidance on timing and operational details to avoid market disruption.
3. Coordinate with prudential supervisors: Ensure liquidity coverage, capital adequacy, and resolution frameworks support financial stability when changing liquidity regulation.
4. Consider targeted measures: Use targeted or temporary liquidity tools in crises rather than permanent blunt reserve-ratio changes when appropriate.
For businesses and consumers
1. Understand bank safety and deposit protections: Check deposit insurance limits (e.g., FDIC in the U.S.) and how your funds are distributed across banks.
2. Monitor credit conditions: Changes in reserve policy can affect loan availability and rates; time borrowing decisions accordingly.
3. Diversify funding and banking relationships: For firms, diversify cash and credit lines across institutions to reduce exposure to a single bank’s liquidity constraints.
4. Keep emergency cash reserves: Households and businesses should maintain a buffer of liquid savings in case short-term funding or credit tightens.
Bottom line
Reserve requirements are a long-standing tool for ensuring bank liquidity and for influencing overall credit creation. Over time, central banks—particularly the Federal Reserve—have supplemented and partially displaced reserve ratios with interest-rate tools (including paying interest on reserves), open-market operations, and macroprudential regulation. In the U.S., reserve requirements were set to 0% in March 2020, shifting the Fed’s emphasis toward other liquidity-management instruments. Reserve ratios remain an important concept for understanding banking liquidity, but in practice policymakers now operate with a broader toolkit.
Sources and further reading
– Federal Reserve Board — “Reserve Requirements”
– Federal Reserve — “Interest on Reserve Balances”
– Federal Reserve Bank — “Navigating Constraints: The Evolution of Federal Reserve Monetary Policy, 1935–59”
– Federal Reserve Board — “The History of Cyclical Macroprudential Policy in the United States”
– Federal Reserve — “Frequently Asked Questions” (on reserve requirements and related tools)
– U.S. Government Accountability Office — “Observations on Regulation D and the Use of Reserve Requirements”
– Federal Reserve Bank of Cleveland — “A Brief History of Bank Capital Requirements in the United States”
– Investopedia — “Required Reserves” (source provided)
Editor’s note: The following topics are reserved for upcoming updates and will be expanded with detailed examples and datasets.