Fisher's argument to show the passiveness of prices takes the form of a _reductio ad absurdum_. "To show the untenability of such an idea let us grant for the sake of argument that--in some other way than as effect of changes in M, M', V, V', and the Q's--the prices in (say) the United States are changed to (say) double the original level, and let us see what effect this will produce on the other magnitudes in the equation."[333] Then, if the equation of exchange is to be maintained, either M or M' or their velocities must be increased, or trade must be reduced. But he holds that none of these is possible. (1) Money will be reduced. High prices drive money away to other countries. Nor can gold come in via the mints. "No one will take bullion to the mints when he thereby loses half its value."[334] On the contrary, men will melt down coin. Nor will high prices stimulate mining. Rather, by raising the expenses of mining, they will discourage mining. (2) Bank-deposits cannot increase. Bank-deposits depend on the amount of money, and as that is reduced, they must be reduced, to keep their normal ratio to the volume of money. (3) The appeal to velocities is no more satisfactory. These have been already adjusted to individual convenience.[335] (4) Nor can trade be decreased. Since the average person will not only pay, but also receive, high prices, there is no reason why he should reduce his purchases. "_The price-level is normally the one absolutely passive element in the equation of exchange._"[336] "But though it is a fallacy to think that the price-level in one community can, in the long run, affect the money in _that_ community, it is true that the price-level in one community may affect the money in _another_ community. This proposition has been repeatedly made use of in our discussion, and should be clearly distinguished from the fallacy above mentioned. The price-level in an outside community is an influence outside the equation of exchange of that community, and operates by affecting its money in circulation and not by directly affecting its price-level. _The price-level outside New York City, for instance, affects the price-level in New York City only_ via _changes in the money in New York City_."[337]...