08 
MIGRATION AND BUSINESS CYCLES 
In Chart 15 we have the relation of factory employment to male 
immigration in the three years 1893 to 1895 presented in four dif- 
ferent ways. These four charts, though based on the same fun- 
damental data, do not look closely similar nor do they convey the 
same Impression. 
In Fig. A, the series are expressed as percentage deviations from 
their computed trends. The impression received from this section 
of the chart is that fluctuations in employment are relatively minor 
as compared with those of immigration. This is literally correct, 
but the resulting impression is misleading, for the chart conveys no 
suggestion of the fact that a one per cent fluctuation in employment 
involves a much larger number of men than a one per cent change in 
immigration. Nor is it easy to determine from Fig. A whether the 
fluctuations of the two series are substantially similar in timing 
and direction. Ease of comparison in timing and direction of move- 
ment is obtained by presentation in the form shown in Fg. B; 
that is, with the data expressed as deviations from their trends 
measured in terms of the typical deviation of each respective series. 
This latter method, which has been used in several of the charts in 
this book, has the distinct advantage of throwing the curves close 
together and thus facilitating comparison of their changes in direc- 
tion, but, to avoid false impressions, it should be noted that the 
numerical significance of a given change is almost entirely concealed. 
On such a curve the change in immigration may appear exactly 
equal to that in employment, but we cannot tell from the curve 
whether the number of men represented by the change in employ- 
ment is equal to the number affected by the change in immigration 
or, possibly, one hundred times as great. 
For reasons which will be more obvious as we note the many 
possible bases of comparison, it is practically impossible to select 
scales which will give a precise and unquestionably true impression 
of the relative numerical importance of the changes in employment 
and immigration. However, if we are turning our attention to the 
relation of changes in the volume of employment and immigration, 
in terms of the number of persons affected, rather than to the 
timing and direction of such changes, then a more accurate impres- 
sion is probably obtained by the use of charts similar to those found 
in Fig. C and Fig. D of Chart 15. 
In Fig. C the fluctuations in employment are emphasized by the 
use of a larger scale than that used for immigration, so that a devia- 
tion of one per cent in employment appears as great as a ten per