§ 3. #Commercial bank deposits of an investment nature.# If a commercial bank pays no interest on demand deposits there is no motive for the depositor to keep a balance larger than he needs as current purchasing power. When his bank account increases beyond that point, it becomes available for a more or less lasting investment to yield financial income. If the sum is small or if the owner is at all uncertain as to his plans or if he is not in a position to find another attractive form of investment, the offer by the bank of a small rate of interest on special time deposits (2 to 3 per cent is not an unusual rate in such cases) will suffice to cause him to leave such funds in the bank. Since about 1900 the practice has been greatly extended of paying interest even on "current balances" of regular checking accounts (demand deposits). If the new 5 per cent rule[4] as to reserves against time deposits operates to cause commercial banks generally to pay a rate ranging from 2-1/2 to 3-1/2 per cent on time deposits, their amount will doubtless increase greatly. But still, in the future as in the past, those depositors having funds that can be invested for considerable periods will seek a higher rate of interest than can be obtained from commercial banks. In their loaning function the "commercial" banks (as the adjective indicates) serve mainly the special needs of the _commercial_ elements of the community--business men borrowing for short terms to carry out particular transactions. Loans made on short-time commercial paper (quick assets) are very suitable to the needs of a bank that has its liabilities largely in the form of demand deposits. Time deposits can be more safely loaned on the security of real estate and for longer periods. Despite their limitations in this respect, the commercial banks must be recognized as of growing importance in the work of encouraging and collecting small savings, which in many cases are better invested in other ways. In 1916, the centenary of the beginning of savings banks in this country, a nation-wide propaganda was undertaken by the American Bankers' Association for the encouragement of savings. § 4. #Investment banking#. Enormous amounts of securities issued by governments or by corporations (railroad or industrial) are now on the market and to be bought conveniently by private investors. Through special bond houses some bonds are to be had in denominations as small as $100 and $500. The regular brokers on the stock exchanges buy and sell, for a small commission, the regular bonds and investment stocks. Several large statistical and financial expert agencies[5] in return for an annual subscription, offer advice to investors regarding general market conditions and special securities.