ys buy the product of
another unit of labor _aided by capital_--we must take _all
pains_ to avoid.

In connection with the cost in labor of different articles
it is to be remembered that in agriculture the effect of
improvements of method may not always suffice to counteract
the working of the so-called law of diminishing returns,
which insures, with agricultural science in a given state of
advancement, smaller products per capita when there are more
men on a given area. That this influence should preponderate
over that of improved processes requires that population
should increase with a degree of rapidity which may or may
not be maintained.

CHAPTER XIII

THE LIMITS OF AN ECONOMIC SOCIETY

When we try to establish a standard to which wages generally tend to
conform, the question arises how much of the earth we have in view. Is
there a rate at which the pay of labor in Europe, Asia, Africa,
Australia, and America tends to settle and remain? Is there a common
rate of interest that is normal in all these grand divisions, and are
there also general standards of value for goods which govern their
prices in all the markets of the world? If there are no such standards
having universal validity, are there any that are valid within single
geographical divisions? On what principle can we divide the earth into
sections for economic purposes? These are some of the questions which
must be answered if a theory of distribution is to have any
definiteness of meaning, and they arise whenever we try to establish a
static standard of any kind. If we talk about natural wages, we must
know in how much of the world they are natural. The questions become
even more urgent when we try to solve dynamic problems. We shall have
to determine the effects of an influx of labor into the economic
society we are studying; but does this mean an increase of population
in the world as a whole? Does an influx of capital have a similar
comprehensive meaning, and does an improvement in the method of
producing some commodity mean a change in the mode of making it in
every part of the world where it is produced at all? We need to know
how extensive the society is whose activities we are examining.

_Characteristics of an Economic Society._--We have said that there are
natural rates of wages, etc., within some area, which we have regarded
as containing an economic society, and we have treated this