Effect of a Single Improvement is Limited._--In
the case of consumers' goods improvements are going on so nearly
incessantly and at so many points that the effect is much the same as
if every invention cheapened most of them at once. Harmful
disturbances are reduced to minute dimensions by the multiplying of
the changes, each of which, if it occurred alone, would produce a
hurtful effect. Many inventions cancel one another's unfavorable
effects in a way that we shall later examine. What we now have to do
is to isolate a single productive change and see whether there are
forces working to reduce its own independent power to create
incidental disturbance. What limits the power of a single new and
economical process to eject laborers from their accustomed places of
employment? This question cannot here be answered in detail, but a
brief statement will cover the general principles involved. Obviously
the displacement varies inversely with the extent to which increased
cheapness enlarges the consumption of the article affected. If by
making one thousand men produce as much of the commodity as two
thousand formerly produced, you so reduce costs as to double the
consumption of the article, you keep all the men who formerly made it
in their accustomed places of employment. The elasticity of the want
itself to which the article caters is one of the two elements that
determine the increase in the consumption of it; but when this
increase is due to an extensive substitution of this article for
others in the purchasing lists of the consuming public, the result is
greatly to reduce the displacement of labor which the new and
economical method of production entails. Such substitutions are very
general and are a large factor in rescuing men from the hardship of
being forced out of the employments they are used to.

_On what an Enlarging Market for Tools and Raw Materials
Depends._--The market for raw materials and tools depends on that for
consumers' goods in their completed state. If _A_, the raw material,
_enters only into A'''_, it can be sold in increasing quantities only
as _A'''_ is thus sold. The chief fact about tools and materials is
that they may contribute to a large number of completed goods, and the
significance of this fact we shall soon see. The ultimate power to
find a market for all products of the lower subgroups depends on
finding one for the products of the uppermost ones--the _A'''_,
_B'''_, and _C'''_ of our ta