# Modern Money Mechanics/Bank Deposits—How They Expand or Contract

Bank Deposits—How They Expand or Contract
Let us assume that expansion in the money stock is desired by the Federal Reserve to achieve its policy objectives. One way the central bank can initiate such an expansion is through purchases of securities in the open market. Payment for the securities adds to bank reserves. Such purchases (and sales) are called "open market operations."
How do open market purchases add to bank reserves and deposits? Suppose the Federal Reserve System, through its trading desk at the Federal Reserve Bank of New York, buys $10,000 of Treasury bills from a dealer in U. S. government securities. In today's world of computerized financial transactions, the Federal Reserve Bank pays for the securities with an "electronic" check drawn on itself. Via its "Fedwire" transfer network, the Federal Reserve notifies the dealer's designated bank (Bank A) that payment for the securities should be credited to (deposited in) the dealer's account at Bank A. At the same time, Bank A's reserve account at the Federal Reserve is credited for the amount of the securities purchase. The Federal Reserve System has added $10,000 of securities to its assets, which it has paid for, in effect, by creating a liability on itself in the form of bank reserve balances. These reserves on Bank A's books are matched by $10,000 of the dealer's deposits that did not exist before. See illustration 1.

##### How the Multiple Expansion Process Works

If the process ended here, there would be no "multiple" expansion, i.e., deposits and bank reserves would have changed by the same amount. However, banks are required to maintain reserves equal to only a fraction of their deposits. Reserves in excess of this amount may be used to increase earning assets — loans and investments. Unused or excess reserves earn no interest. Under current regulations, the reserve requirement against most transaction accounts is 10 percent. Assuming, for simplicity, a uniform 10 percent reserve requirement against all transaction deposits, and further assuming that all banks attempt to remain fully invested, we can now trace the process of expansion in deposits which can take place on the basis of the additional reserves provided by the Federal Reserve System's purchase of U. S. government securities.
The expansion process may or may not begin with Bank A, depending on what the dealer does with the money received from the sale of securities. If the dealer immediately writes checks for $10,000 and all of them are deposited in other banks, Bank A loses both deposits and reserves and shows no net change as a result of the System's open market purchase. However, other banks have received them. Most likely, a part of the initial deposit will remain with Bank A, and a part will be shifted to other banks as the dealer's checks clear.
It does not really matter where this money is at any given time. The important fact is that these deposits do not disappear. They are in some deposit accounts at all times. All banks together have $10,000 of deposits and reserves that they did not have before. However, they are not required to keep $10,000 of reserves against the $10,000 of deposits. All they need to retain, under a 10 percent reserve requirement, is $1000. The remaining $9,000 is "excess reserves." This amount can be loaned or invested. See illustration 2.
If business is active, the banks with excess reserves probably will have opportunities to loan the $9,000. Of course, they do not really pay out loans from the money they receive as deposits. If they did this, no additional money would be created. What they do when they make loans is to accept promissory notes in exchange for credits to the borrowers' transaction accounts. Loans (assets) and deposits (liabilities) both rise by $9,000. Reserves are unchanged by the loan transactions. But the deposit credits constitute new additions to the total deposits of the banking system. See illustration 3.

### Deposit Expansion

| 1 | When the Federal Reserve Bank purchases government securities, bank reserves increase. This happens because the seller of the securities receives payment through a credit to a designated deposit account at a bank (Bank A) which the Federal Reserve effects by crediting the reserve account of Bank A. |
| Assets | Liabilities |
| U.S. government securities + 10,000 | Reserve accounts: Bank A + 10,000 |
| Assets | Liabilities |
| Reserves with F.R. Banks+ 10,000 | Customer deposit+ 10,000 |
| 2 | As a result, all banks taken together now have "excess" reserves on which deposit expansion can take place. Total reserves gained from new deposits...... 10,000 less: required against new deposits (at 10 percent).............................. 1,000 equals: Excess reserves ............................. 9,000 |
| 3 | Expansion takes place only if the banks that hold these excess reserves (Stage 1 banks) increase their loans or investments. Loans are made by crediting the borrower's account, i.e., by creating additional deposit money. STAGE 1 BANKS Assets Liabilities Loans+ 9,000 Borrower deposits+ 9,000 |
This is the beginning of the deposit expansion process. In the first stage of the process, total loans and deposits of the banks rise by an amount equal to the excess reserves existing before any loans were made (90 percent of the initial deposit increase). At the end of Stage 1, deposits have risen a total of $19,000 (the initial $10,000 provided by the Federal Reserve's action plus the $9,000 in deposits created by Stage 1 banks). See illustration 4. However, only $900 (10 percent of $9000) of excess reserves have been absorbed by the additional deposit growth at Stage 1 banks. See illustration 5.
The lending banks, however, do not expect to retain the deposits they create through their loan operations. Borrowers write checks that probably will be deposited in other banks. As these checks move through the collection process, the Federal Reserve Banks debit the reserve accounts of the paying banks (Stage 1 banks) and credit those of the receiving banks. See illustration 6.
Whether Stage 1 banks actually do lose the deposits to other banks or whether any or all of the borrowers' checks are redeposited in these same banks makes no difference in the expansion process. If the lending banks expect to lose these deposits - and an equal amount of reserves - as the borrowers' checks are paid, they will not lend more than their excess reserves. Like the original $10,000 deposit, the loan-credited deposits may be transferred to other banks, but they remain somewhere in the banking system. Whichever banks receive them also acquire equal amounts of reserves, of which all but 10 percent will be "excess."
Assuming that the banks holding the $9,000 of deposits created in Stage 1 in turn make loans equal to their excess reserves, then loans and deposits will rise by a further $8,100 in the second stage of expansion. This process can continue until deposits have risen to the point where all the reserves provided by the initial purchase of government securities by the Federal Reserve System are just sufficient to satisfy reserve requirements against the newly created deposits. (See pages 10 and 11.)
The individual bank, of course, is not concerned as to the stages of expansion in which it may be participating. Inflows and outflows of deposits occur continuously. Any deposit received is new money, regardless of its ultimate source. But if bank policy is to make loans and investments equal to whatever reserves are in excess of legal requirements, the expansion process will be carried on.

##### How Much Can Deposits Expand in the Banking System?

The total amount of expansion that can take place is illustrated on page 11. Carried through to theoretical limits, the initial $10,000 of reserves distributed within the banking system gives rise to an expansion of $90,000 in bank credit (loans and investments) and supports a total of $100,000 in new deposits under a 10 percent reserve requirement. The deposit expansion factor for a given amount of new reserves is thus the reciprocal of the required reserve percentage (1/.10 = 10). Loan expansion will be less by the amount of the initial injection. The multiple expansion is possible because the banks as a group are like one large bank in which checks drawn against borrowers' deposits result in credits to accounts of other depositors, with no net change in the total reserves.

##### Expansion through Bank Investments

Deposit expansion can proceed from investments as well as loans. Suppose that the demand for loans at some Stage 1 banks is slack. These banks would then probably purchase securities. If the sellers of the securities were customers, the banks would make payment by crediting the customers' transaction accounts, deposit liabilities would rise just as if loans had been made. More likely, these banks would purchase the securities through dealers, paying for them with checks on themselves or on their reserve accounts. These checks would be deposited in the sellers' banks. In either case, the net effects on the banking system are identical with those resulting from loan operations.
| 4 | As a result of the process so far, total assets and total liabilities of all banks together have risen 19,000. ALL BANKS Assets Liabilities Reserves with F. R. Banks+ 10,000 Loans+ 9,000 Total+ 19,000 Deposits: Initial + 10,000 Stage 1 + 9,000 Total + 19,000 |
| 5 | Excess reserves have been reduced by the amount required against the deposits created by the loans made in Stage 1. Total reserves gained from initial deposits..................... 10,000 less: Required against initial deposits......... 1,000 less: Required against Stage 1 deposits....... 900....... 1,900 equals: Excess reserves............................................... 8,100 |
| 6 | ...because borrowers write checks on their accounts at the lending banks. As these checks are deposited in the payees' banks and cleared, the deposits created by Stage 1 loans and an equal amount of reserves may be transferred to other banks. STAGE 1 BANKS Assets Liabilities Reserves with F. R. Banks - 9,000 Borrower deposits - 9,000 |
| Assets | Liabilities |
| | Reserve accounts: Stage 1 banks - 9,000 Other banks + 9,000 |
| Assets | Liabilities |
| Reserves with F.R. Banks + 9,000 | Deposits + 9,000 |
| 7 | Expansion continues as the banks that have excess reserves increase their loans by that amount, crediting borrowers' deposit accounts in the process, thus creating still more money. STAGE 2 BANKS Assets Liabilities Loans + 8,100 Borrower deposits + 8,100 |
Footnotes
* ↑ Dollar amounts used in the various illustrations do not necessarily bear any resemblance to actual transactions. For example, open market operations typically are conducted with many dealers and in amounts totaling several billion dollars.
* ↑ Indeed, many transactions today are accomplished through an electronic transfer of funds between accounts rather than through issuance of a paper check. Apart from the time of posting, the accounting entries are the same whether a transfer is made with a paper check or electronically. The term "check," therefore, is used for both types of transfers.
* ↑ For each bank, the reserve requirement is 3 percent on a specified base amount of transaction accounts and 10 percent on the amount above this base. Initially, the Monetary Control Act set this base amount - called the "low reserve tranche" — at $25 million, and provided for it to change annually in line with the growth in transaction deposits nationally. The low reserve tranche was $41.1 million in 1991 and $42.2 million in 1992. The Garn-St. Germain Act of 1982 further modified these requirements by exempting the first $2 million of reservable liabilities from reserve requirements. Like the low reserve tranche, the exempt level is adjusted each year to reflect growth in reservable liabilities. The exempt level was $3.4 million in 1991 and $3.6 million in 1992.