FOREWORD 
chairman, Professor John R. Commons, Professor John A. Fairlie, 
Dr. Robert F. Foerster, Professor Edward A. Miller, Professor 
Charles E. Merriam, Professor Frederick A. Ogg, Professor Carl 
Wittke, and the writer. The plan of co-operation between the old 
Committee and the new one transferred the ‘“‘machinization study” 
to the Social Science Research Council, under whose auspices it 
has been carried nearly to completion by Dr. Jerome. 
Finally, the Social Science Research Council has enabled the 
National Bureau to supplement the present study of short-period 
fluctuations of migration in the United States by a long-period in- 
vestigation of mass movements of mankind over the earth. Of 
course, the preparation of a broad sketch of the great world migra- 
tions of the past three or four generations requires the critical 
examination of many estimates of population movements for years 
and countries in which accurate records are lacking. It requires 
also the use of all the relevant statistics compiled in any part of 
the world. In short, it is a project which calls for close inter- 
national co-operation among the leading authorities upon population 
statistics. Dr. Walter F. Willcox, of Cornell University, is organ- 
izing this co-operation with the National Bureau, and, when the 
materials are assembled, he will prepare a report. 
Like the National Research Council, the Social Science Research 
Council asked and obtained financial support for its migration studies 
from the Laura Spelman Rockefeller Memorial. 
Belonging as it does to two series of studies, Migration and 
Business Cycles is designed to cover a limited field. The major 
issues with which it deals are summed up in two questions: 
(1) To what extent are fluctuations in migration at- 
tributable to fluctuations in employment? 
(2) To what extent, in turn, are fluctuations in 
migration an ameliorating influence, and to what 
extent an aggravating factor, in employment 
and unemployment fluctuations? 
Dr. Jerome has sought to get the most definite answers to these 
questions which he can wring from the available records. Other 
phases of the problem he treats incidentally, if at all. Among the 
factors affecting migration which he passes over lightly are political 
conditions, steerage rates, and the methods adopted by steamship 
companies to stimulate passenger traffic. A scientific analysis of 
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