The Fed uses three main monetary policy tools in order to
regulate the money supply and bank lendings. They are, discount
rate, open market operations and the reserve requirements.
To increase the bank lendings the money supply within the
economy must Increase.
This happens when the Fed makes some purchases, lowers the
discount rate and the reserve requirements.
Selling of bonds, raising required reserve ratio and discount
rate will only decrease the money supply and thereby decrease bank
lendings.
But when the Fed lowers the discount rate from 4 to 2 percent,
the banks can give out more loans as they will be having enough
reserves left even after giving out the loans.