Final answer:
The Federal Reserve requires commercial banks to have reserves to ensure liquidity, control the money supply, and provide stability.
Step-by-step explanation:
The Federal Reserve requires commercial banks to have reserves for several reasons. First, it helps ensure that banks have enough money to meet the demands of depositors who want to withdraw their money. This prevents banks from failing due to a sudden increase in withdrawals. Second, it allows the Federal Reserve to control the money supply and stabilize the economy. By manipulating the reserve requirements, the Fed can influence how much money banks can lend out, which affects interest rates and inflation. Finally, reserves act as a form of insurance for banks, providing a cushion to absorb losses and maintain financial stability.