vacated places, and the struggle of force will begin. Slugging may
ensue and may go to the limit of a weak government's toleration. The
more complete is the exclusion of free labor, the higher is the rate
which organized labor secures; but this rate always falls within a
certain distance of the normal one, as that is fixed by the final
productivity of social labor. Even the pay secured by violent strikes
is, as we have already shown, _governed by_ the law of final
productivity, though it does not _coincide with_ that rate. Actual pay
and standard pay are like a vessel and a tug attached to each other by
a hawser, which allows one to drift far from the other but does not
let them part company. In the long run the tug takes the tow with it.
Even the wages which a trust gives to a fighting union--wages paid by
a monopoly to a monopoly--are governed by the law of final
productivity, since there is a limit on what the trust can extort from
the public, and there is a limit on what the union can extort from the
trust. Potential competition, by limiting both the producing
corporation and the trade union, vindicates the natural law of wages,
though its results are made inexact by monopoly.

_How Potential Competition affects Organized Labor._--We have seen
that potential competition keeps within limits the prices of goods
made by trusts. If they become too high, new mills are built. In a
like way potential competition puts a check on the wages a strong
union can secure; for if these are too far above the level of
non-union men's pay, such men will find their way into the business.
Open shops will be established, either by the present employers or by
new ones. There will be much to be gained by an independent shop
manned by non-union labor, and the danger of this makes a trade union
more conservative than it would otherwise be. The chief potentiality
in the case is that of the new and independent shop, and if the way is
open for this to appear, the range of difference between the pay of
favored laborers and that of others is greatly reduced. The trade
union may be able to carry its point and keep free labor from its
field, so long as it has only its own employers to deal with; but if
new employers will appear whenever there is an inducement to do so,
the case is quite otherwise. The new mills make the greater gains if
they are manned by non-union men.

With the field open for all producers, the danger of free shops with
free m