If the Fed wants to increase money supply, it should make an open market purchase of $20 billion which would increase money supply by $100 billion.
If the Fed wants to decrease the money supply, then an open market sale of $30 billion would decrease money supply by $150 billion.
They can engage in an open market purchase of government securities which would lead to more dollars entering the market.
The increase in money supply is:
= Amount of purchase / Reserve requirement
= 20 billion / 0.2
= $100 billion
An open market sale of government securities would take money out of the economy and reduce money supply by:
= Amount of sale / Reserve requirement
= 30 billion / 0.2
= $150 billion
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