MIGRATION AND BUSINESS CYCLES 
discussed, male immigration is of greatest significance for our 
purpose, and, consequently in the more detailed analysis based 
upon quarterly and monthly data, we have, where convenient, 
made use of the statistics of male immigration rather than of the 
totals for both sexes. 
Adjustment for a Variable Seasonal. 
In analyzing the fluctuations of quarterly male immigration, the 
typical seasonal element has been, so far as practicable, eliminated 
and the adjusted fluctuations expressed as deviations from a twenty- 
CHART 12 
CYCLES IN QUARTERLY IMPORTS OF MERCHANDISE AND IN MALE 
IMMIGRATION: 1868-1889 
Adjusted for typical seasonal variation 
Unit= one standard deviation 
+2.0- 
i 
of 5) of 
1.0 a J 
oligo, oe | s. FEEEIEES EEE BE ei [a Fo 185 
«Numerical data in Table 19. 
eight quarter moving average. In thus correcting for seasonal 
variation, allowance was made for a seasonal influence which varies 
at different stages in the cycle, in order to conform to the fact, 
revealed by examination of the raw data, that the seasonal fluctua- 
tion experiences somewhat regularly a damping down in the de- 
pression period of each cycle. In other words, the seasonal is itself 
subject to a cyclical variation. 
Inasmuch as during most of the period prior to 1890 quarterly 
figures on production or employment are not available, we have 
used quarterly statistics of merchandise imports as a rough measure 
of industrial activity in the years 1868 to 1889. The import figures, 
like the immigration data, have been adjusted for a changing normal 
seasonal variation and expressed as deviations from a twenty-eight 
quarter moving average. 
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