4 MIGRATION AND BUSINESS CYCLES 
arate chapters which it is impracticable to repeat here in detail 
but to which some weight must be given in interpreting the signi- 
ficance of the tendencies here set forth. However, the various 
irregularities and exceptions which have been noted are by no means 
adequate to impair seriously the validity of the general conclusion 
that there is a close relation between cyclical and seasonal fluctua- 
tions in employment and the corresponding ar in migration. 
That this correspondence is more than a mere coincidence is 
suggested by the fact that, particularly for the cyclical fluctuations, 
there are a priori reasons for expecting that migration would be 
sensitive to employment conditions, and also by the further fact 
that when the migratory currents are separated into their several 
elements, it is found that it is just those elements which one would 
expect to be swayed in their choice of the particular time of arrival 
and departure by variations in the prospect of employment which 
do show, in fact, the closest correlation with employment conditions. 
The movements of those immigrants who have no gainful occupation 
are decidedly less responsive than the movements of the working 
element to cyclical and seasonal variations in employment. 
Significant Differences in Cycles of Employment and Migration. 
A close scrutiny of the cyclical movements of employment and 
migration reveals the fact that despite the general similarity in the 
appearance of the curves representing these series, there are also 
noteworthy differences. First, there are irregular fluctuations in 
immigration which cannot be readily explained merely by reference 
to the course of industrial activity. The relatively slight amount of 
immigration during the industrial activity of the war period affords 
an obvious example. 
In the second place, even where the fluctuations of the several 
series are obviously interrelated, there are differences in the time at 
which the changes occur, in their relative violence, and in the 
number of persons directly affected. A recognition of these dif- 
ferences is essential to a clear understanding of the problem. 
Frequently the turns in the migration movement lag behind the 
corresponding change in employment, indicating that the passage 
of some time is required before the full effect of a change in employ- 
ment is felt upon migration. The extent of this lag varies in different 
cycles, and is also frequently found to vary on the downturn and the 
upturn of the same cycie. 
In a few instances the effect of a change in employment conditions 
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