Economics Question

if banks reduse the reserve ratio ,banks can make more loads,credit creation can be processed throuh the banking multiplier(reserve ratio 100% do not have any credit creation)so,depost can increase through the banking mulitipier,money supply is combimed with cash held by non-bank sector and deposit.
Therefore,deposit increase and the money supply increase!

Money multiplier (Creation) = Money / Required reserve ratio

Eg. Now there is $10,000 and the required reserve ratio is 40%. A deposit this money to bank, and bank can save $4,000 ($10,000 * 40%) for required reserve and lend out the rest $6,000 to B. Then B get it and spend to C. C deposit it to bank, and bank can save $2,400 ($6,000 * 40%) for required reserve and lend out the rest $3,600 to D. D will then......, everlasting until the end. There will be totally $10,000 cash at bank, $25,000 deposit and $15,000 loan to outsiders. The $15,000 is created by the REQUIRED RESERVE RATIO, which is the increase in money supply.

If the required reserve ratio is set to 100%, that mean bank cannot lend it out. So we can conclude that banks can control and affect the money supply if the required reserve ratio is less than 100%.

required reserve ratio is reduced；
discount rate is reduced；
the government buy the bonds from the open market；
the government issue more notes or coins

these four factor will increase money supply (Ms)