How do central banks influence money supply?

• A. Through monetary policy tools such as open market operations, reserve requirements, and policy rate adjustments.
• B. By setting national tax policies.
• C. By regulating consumer credit scores.
• D. By issuing public bonds to finance government deficits.

Answer: (A)

Central banks influence the money supply primarily through monetary policy tools that manage bank reserves and interest rates. Open market operations—buying or selling government securities—change the amount of reserves banks hold. When the central bank buys securities, it injects reserves into the banking system, encouraging more lending and expanding the money supply; selling securities drains reserves and contracts lending and the money supply.

Reserve requirements set the minimum fraction of deposits banks must hold as reserves. Lowering these requirements frees up more funds for banks to lend, boosting the money supply; raising them has the opposite effect.

Policy rate adjustments set the cost of borrowing in the economy. Lower policy rates reduce borrowing costs, stimulating lending and spending and increasing the money supply; higher rates slow lending and shrink the money supply.

Other options aren’t central-bank tools for controlling money supply: taxes are fiscal policy; credit score regulation is about credit reporting, not money supply; and issuing public bonds is a government financing activity, not a direct central-bank mechanism to control money supply (though central banks may influence bond markets in other ways).