42 
INTERNATIONAL TRADE 
mental thing in the movement of domestic prices, as distinct 
from international, is the movement of money incomes; and 
among these, again, the basic are the wages of manual labor, such 
as are usually registered in the index numbers of wages. Here 
is the item that is most significant and most easy to interpret and 
follow. Changes in money wages, so far as peculiar to a given 
country — so far as due, that is, to causes affecting it alone, and 
not a reflex of a general movement appearing throughout the com- 
mercial world — are at once the first indicator of changes on 
other domestic “prices”, and also the effective mechanism through 
which the greater or less gain from international trade is trans- 
mitted to the several peoples. It is this which should especially 
be watched, and it is this, fortunately, which the statistical mate- 
rial, when available at all, is most likely to lay bare.