en unexpected interconnections between different industries and
different markets. To gape at these complexities in a confused stupor
is as foolish as it is to ignore them. But confusion and stupor are
only too likely to represent our final state of mind, if we attempt to
deal with these complications, one by one as they occur to us, in a
piecemeal and haphazard fashion. We need a clear method, a systematic
plan by which we may search them out, and fit them into place. The
four relations which we have enumerated supply us with such a plan and
method. For they represent something more than a series of pompous
names for familiar notions. They constitute a classification of the
various ways in which the demand and supply of one thing can affect
the demand and supply of others; a classification which is exhaustive
when we add the relation of derived demand, and an analogous relation
on the supply side which we must now notice.

Sec.8. _Ultimate Real Costs_. Just as the utility of "producers' goods"
is derived from that of the "consumers' goods" which they help to
make; so the cost of any commodity is derived from the cost of the
things which help to make it. Moreover, just as we recognize that the
utility of "consumers' goods" lies at the back of all demand, and
constitutes the ultimate end of all production; so we cannot but feel,
however obscurely, that behind the phenomena of money costs, there
must lie certain ultimate costs, of which all money costs are but the
measure. But when we try to explain what the nature of these real
costs may be, we are plunged in difficulty. Wages, it may indeed seem
at first sight, present no trouble. There is the effort and the
fatigue, the unpleasantness of human labor, to represent real
costs. But can we suppose that these things are measured with any
approach to accuracy by the wages which are paid in actual fact? Is it
true, even as a broad general rule, that the services which are most
arduous and most disagreeable command the highest price? And wages are
not the only ingredient of money costs. There are profits: to what
real costs do profits correspond? More difficult still, to what does
rent correspond? These plainly are not questions upon which he who
runs may read. It will be necessary to devote the next four chapters
to their elucidation.

CHAPTER VI

LAND

Sec.1. _The Special Characteristics of Land_. In the great process of
co-operation by which the wants of mankin