nceivably, still be used as the medium of exchange, but it
would--unless protected by legislation or otherwise from the operation
of economic law, and so given a monopoly-price--have an exchange-value
equal to that of coal, a ton of the one being equal to a ton of the
other--provided, of course, that its utility remained. Since the
scarcity of gold is an important element in its utility valuation,
creating and fostering the desire for its possession, that utility-value
might largely disappear if gold became as plentiful as coal, in which
case it would not have the same value as coal, and might cease to be a
commodity at all.

Price, then, is the expression of value in terms of some other
commodity, which, generally used for that purpose of expressing the
value of other commodities, we call money. It is only an approximation
of value, and subject to a much greater fluctuation than value itself.
It may, for a time, fall far below or rise above value, but in a free
market--the only condition in which the operation of the law may be
judged--sooner or later the equilibrium will be regained. Where monopoly
exists, the free market condition being non-existent, price may be
constantly elevated above value. Monopoly-price is an artificial
elevation of price above value, and must be considered separately as the
abrogation of the law of value.

Failure to discriminate between value and its price-expression, or
symbol, has led to endless difficulty. It lies at the bottom of the
naive theory that value depends upon the relation of supply and demand.
Lord Lauderdale's famous theory has found much support among later
economists, though it is now rather unpopular when stated in its old,
simple form. Disguised in the so-called Austrian theory of final
utility, it has attained considerable vogue.[172] The theory is
plausible and convincing to the ordinary mind. Every day we see
illustrations of its working: prices are depressed when there is an
oversupply, and elevated when the demand of would-be consumers exceeds
the supply of the commodities they desire to buy. It is not so easy to
see that these effects are temporary, and that there is an automatic
adjustment going on. Increased demand raises prices for a while, but it
also calls forth an increase in supply which tends to restore the old
price level, or may even force prices below it. In the latter case, the
supply falls off and prices find their real level. The relation of
supply t