SEASONAL FLUCTUATIONS 35 
tember, the increase in employment exceeds the net volume of male 
arrivals. In October and November a decrease in employment is 
accompanied by a small net immigration, and in December a heavy 
decrease in employment is accompanied by a small excess of de- 
parting over arriving male aliens. 
In other words, decreasing employment in January and November 
is aggravated by a small net excess of arrivals, and in October by 
net arrivals to the number of about 32,000. Also, in April, July, and 
September, the increase in employment is not sufficient to absorb the 
new arrivals. 
Only in December, and then only to a small extent, is the slack 
created by a decrease in employment taken up in part by a net outgo 
of male aliens. 
It is true that in five months—February, March, May, June, and 
August—the number of workers employed is increasing faster than 
the net inflow of male aliens, and if there chances to be a shortage of 
resident workers in these months, immigration may be looked upon 
as alleviating this shortage. On the other hand, if in these months 
the increase in employment is in fact not adequate to relieve an 
existing unemployment situation, then the net inflow of alien wor- 
kers merely acts to check the decrease in unemployment. 
In summarizing the above comparison of the typical net move- 
ment of alien males with the month-to-month change in employment 
ascribed to the growth and seasonal factors, it should be noted that 
the evidence presented should at best be taken as suggestive rather 
than conclusive. The data upon which the estimates are based are 
too fragmentary, and the margin of error involved in the computa- 
tions too large, to justify treating the computed relations as more 
than rough approximations. Here, as in the greater part of this 
chapter, we are dealing with pre-war, and hence pre-restriction, 
conditions. 
With the above qualifications in mind, we may summarize the 
evidence presented in Chart 55 and the accompanying tables as 
indicating that the seasonal distribution of male immigration and 
emigration is such as to aggravate unemployment in six months 
of the year and to alleviate it slightly in one. In the other five 
months, being those in which net male immigration is less than 
the increase in employment, its effect is to alleviate the effects 
of a shortage of resident workers, if such a shortage exists. 
In Fig. B of Chart 55, a comparison similar to that just made for 
24