MIGRATION AND BUSINESS CYCLES 
the 1921 restrictive law; but the use of the indices so computed 
yields a cycle curve which appears to be a reasonable estimate of 
the post-war cycle in immigration (see Chart 24 in Chapter VI).: 
PRE-WAR SEASONAL TENDENCIES IN ARRIVALS 
In the following pages, we first examine the pre-war seasonal 
movements in arrivals, in departures, and in the net result of ar- 
rivals less departures. We then turn to an examination of the avail- 
able evidence concerning seasonal fluctuations of employment in 
those industries in which immigrants engage in large numbers, in 
order to lay the basis for determining to what extent seasonal 
fluctuations in migration synchronize well with seasonal variations 
in employment opportunities. 
In most cases seasonal changes are described in terms of typical 
seasonal fluctuations, by which is meant that part of the total ob- 
served fluctuations which are, on the average, ascribable to seasonal 
influences as distinguished from the longtime trend and cyclical 
influences; but in one or two instances (see Chart 55) attention 1s 
directed to the crude seasonal distributions, which are the average 
distributions of the data over the months of the year without any 
adjustment for the fact that the distribution may be in part due to 
a growth factor. 
Principal Similarities. 
The major features of the seasonal movements of the various 
groups of immigrants can be quickly noted by scanning Charts 48 
and 49, and the tables upon which they are based. 
For most classes of incoming aliens, the volume is small in Jan- 
uary and February, with an incoming rush in March, April, and 
May, a falling off in midsummer, and a moderate recovery in Sep- 
tember and October, followed by a decline in November and 
December. 
Male and Female Immigration. 
Inasmuch as the movement of male immigration has been the 
primary series used in our analysis of the cyclical aspects of industry, 
it is pertinent to inquire as to what differences exist between the 
seasonal fluctuations of the male immigrant group and those of 
other immigrant groups. 
The Immigration Act of 1924 again modified the seasonal movement in irnmigration 
by its provision that not more than fen per cent of any annual quota may be admitted in 
any month except in cases where such quota is less than 300 for the entire year. 
2919