2 (a).... An increase of wants, by leading to an increase in trade, tends to lower the price level. Historically, during recent times through invention, education, and the emulation coming from increased contact in centers of population, there has been a great intensification and diversification of human wants and therefore increased trade. Consequently, there has been from these causes a tendency of prices to fall. 3 (a). Anything which facilitates intercourse tends to increase trade. Anything that interferes with intercourse tends to decrease trade. First of all, there are the mechanical facilities for transport. As Macaulay said, with the exception of the alphabet and the printing press, no set of inventions has tended to alter civilization so much as those which abridge distance,--such as the railway, the steamship, the telephone, the telegraph, and that conveyer of information and advertisements, the newspaper. These all tend, therefore, to decrease prices. 3 (b). Trade barriers are not only physical but legal. A tariff between countries has the same influence in decreasing trade as a chain of mountains. The freer the trade, the more of it there will be.... 3 (c). The development of efficient monetary and banking systems tends to increase trade. There have been times in the history of the world when money was in so uncertain a state that people hesitated to make many trade contracts because of the lack of knowledge of what would be required of them when the contract should be fulfilled. In the same way, when people cannot depend on the good faith or stability of banks, they will hesitate to use deposits and checks. 3 (d). Confidence, not only in banks in particular, but in business in general, is truly said to be "the soul of trade." Without this confidence there cannot be a great volume of contracts. Anything that tends to increase this confidence tends to increase trade.... We see, then, that prices will tend to fall through increase in trade, which may in turn be brought about by improved transportation, by increased freedom of trade, by improved monetary and banking systems, and by business confidence. Historically, during recent years, all of these causes have tended to grow in power, except freedom of trade.... Having examined those causes outside the equation which affect the volume of trade, our next task is to consider the outside causes that affect the velocities of circulation of money and of deposits. For the most part, the causes affecting one of these velocities affect the other also. These causes may be classified as follows: 1. _Habits of the individual._ (a) As to thrift and hoarding. (b) As to book credit. (c) As to the use of checks. 2. _Systems of payments in the community._ (a) As to frequency of receipts and of disbursements. (b) As to regularity of receipts and disbursements. (c) As to correspondence between times and amounts of receipts and disbursements. 3. _General causes._