THE PROBLEM : 
subject adequately it would be necessary to determine the extent to 
which migration has dominated the direction and the 
amount of industrial growth in the United States—that is, the 
extent to which the major changes in our industrial development 
and occupational distribution have been closely related to changes 
in the volume, type, or geographical distribution of immigration 
and emigration. 
Even more significant would be an inquiry into the readjustments 
which may in the future be set in motion by modifications in the 
volume or type of migration. Will a decrease in the annual acces- 
sion of laborers from abroad set in motion significant readjustments 
in industrial tendencies? Will the vacuum created by restricting 
immigration stimulate internal migration of the negro, intensify the 
country-to-city movement, or lead to a better utilization of the 
available man-power through improvements in methods of or- 
ganization and administration or through more effective labor- 
saving devices? Or, if none of the above developments is adequate 
to enable industries to maintain the customary rate of progress, 
must we see a check to industrial advancement? All these are fas- 
cinating questions worthy of intensive and sustained research, and 
it is hoped that we may in subsequent reports give attention to 
these phases of the problem. The present study is made from what 
we have designated as the short-time point of view. 
Migration and Business Cycles. 
The queries we have just suggested are concerned chiefly with 
long-run tendencies. Equally significant is the relation of migration 
to those fluctuations in industrial activity which mark the various 
stages in the business cycle or accompany the round of the seasons. 
In recent years the attention of students of economic affairs has 
been focused upon the phenomena of the business cycle, with its 
alternating periods of prosperity and depression, and the accom- 
panying pendulum swing of employment from an apparent shortage 
of labor to severe unemployment or a relative surplus of labor. It 
is in this undulation of employment conditions that the most obvious 
and tangible instances of labor surplus and labor shortage arise. 
Demand for labor, like demand for any commodity, means demand 
for a given quantity at a given price. Supply means supply at a 
given price. Labor shortage and labor surplus, consequently, are 
relative terms, to be interpreted in terms of relation to demand at the 
prevailing wages. Obviously, however, if due allowance is made for 
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