nt the
monopoly is untempered by alternative possibilities of transport.

The reverse consideration, the possibility of substituting the article
of monopoly for other articles of consumption, and so securing a wider
market, has quite as important an influence on prices. The possibility
of substituting oil for coal in cooking and certain other operations
has probably a good deal to do with the low price of oil. A Trust will
often keep prices low for a season in order to enable their article to
undersell and drive out a rival article, a competition closely akin to
the competition with a rival producer of the same article. When
natural gas was discovered in the neighbourhood of Pittsburg, the
price was lowered sufficiently to induce a large number of factories
and private houses to give up coal and to burn gas. After expensive
fittings had been put in, and the habit of using gas established, the
Gas Company, without any warning, proceeded to raise the rates to the
tune of 100 per cent. When we ascend to the higher luxuries, the
competition between different commodities to satisfy the same generic
taste, or even to divert taste or fashion from one class of
consumption to another class, is highly complicated, and tempers
considerably the control of a Trust over prices.

The power of a company which holds the patent for a particular kind of
corkscrew is qualified very largely not only by competition of other
corkscrews, but by screw-stoppers and various other devices for
securing the contents of bottles. The ability to dispense with the
object of a monopoly, though it does not prevent the monopolist from
charging prices so much higher than competition prices as to extract
all the "consumer's rent," of the marginal consumer, forms a practical
limit to monopoly prices.

(_c_) Lastly, there is the influence of existing or potential
competition of other producers upon monopoly prices. Where prices and
profits are very high a Trust is liable to more effective competition
on the part of any surviving independent firms, and likewise to the
establishment of new competitors. This ability of outside capital to
enter into competition will of course differ in different trades.
Where the monopoly is protected by a tariff the possibility of new
competition from outside is lessened. When the monopoly is connected
with some natural advantage or the exclusive possession of some
special convenience, as in mining or railways, direct competit