Assume that no banks hold excess reserves, and the public holds no currency. If a bank sells a $100 security to the Fed, explain what happens to this bank and two additional steps in the deposit expansion process, assuming a 10% reserve requirement. How much do deposits and loans increase for the banking system when the process is completed?
Bank A first changes a security for reserves, and then lends the reserves, creating loans. It receives $100 in reserves from the sale of securities. Since all of these reserve will be excess reserves (there was no change in checkable deposits), the bank will loan out all $100. The $100 will then be deposited into Bank B. This bank now has a change in reserves of $100, of which $90 is excess reserves.
Bank B will loan out this $90, which will be deposited into Bank C. Bank C now has an increase in reserves of $90, $81 of which is excess reserves.
Bank C will loan out this $81 dollars and the process will continue until there are no more excess reserves in the banking system. For the banking system, both loans and deposits increase by $1000.