Imagine that the required reserve ratio is 20% and that banks are holding no excess reserves; if the Federal Reserve buys $50 million of bonds from the public, then the total lending capacity of the banking system will
Because the formula for the money multiplier is “M=(1 / required reserve ratio)”, a $50,000,000 injection by the Fed would create 5 times that amount, or $250,000,000, in additional lending capacity.