pays
nothing. The sum of the excesses of service rendered by all
the earlier barrels constitutes what has been called the
consumers' rent, realized in this case from the entire supply
of flour used by the man. In the manner in which it is
conceived and measured this gain has a kinship to genuine
rent.

This surplus is an effect on a man himself. It is not
anything outward or tangible. It exists only in the man's
sensations, and is as far as possible from being a concrete
income in material form traceable to some particular agent.
It can be measured and described in ways that are quite akin
to the manner in which the product of land is measured and
described. Each consists of the sum of a series of surpluses
or differential amounts, and each, moreover, represents a
gain which is not offset by any corresponding subjective
cost. The rent of land must be paid by an _entrepreneur_ and
is a cost in the same sense in which wages and interest are
so; but the owner of the land did not create it by personal
effort or sacrifice.

Analogies between the product of land, or rent, and the
special gains of consumers from the more important parts of
their consumption do exist, but they are overbalanced by
essential differences; and it is better to use the term
_rent_ only in describing the specific contribution to the
material product of industry which a concrete and material
agent makes.

CHAPTER XI

LAND AND ARTIFICIAL INSTRUMENTS

One may hire many things besides land and pay what is commonly called
rent for them. No one would think of calling by any other term the
amount paid for the use of a building, a room in a building, or the
furniture in the room. All these things yield rent to their owners;
and if the intuitions which govern the common use of terms are to be
trusted, the income derived from such things and that derived from
land have some essential qualities in common. Every such income is
paid for the use of some concrete instrument, and is measured, not by
a percentage on the value of the instrument, but by a lump sum--a
certain number of dollars per month or per year.

_The Mode of Calculating the Rent of Concrete Instruments._--Now the
rent of such instruments of production, whether artificial or not, can
be measured in exactly the same way in which the rent of land is
measured. We saw that there are