B68
MIGRATION AND BUSINESS CYCLES
and have beenfused in supplemental studies, but have not been
incorporated in the major index of employment; conditions.
Similar statistics, however, for trade union unemployment in
New York State, by, months, have beenjutilized in widening the
scope of our employment index during the years 1904-1914.
An index of factory employment in New York State is available
beginning in June, 1914, and in the'following year the United States
Bureau of Labor Statistics began an index of factory employment.
In the post-war period still more complete data are available. The
Federal Reserve Board has consolidated various series into an
index of industrial employment for the years 1919 to 1923, and has
also published an “index of the labor market’ showing the fluctua-
tions in the ratio of applicants to jobs in the operations of the
public employment offices during the period January, 1919, to
December, 1923.¢
Previous Studies in Employment Fluctuations.
Several economists have utilized the series described above,
together with supplementary information, in the construction of
more or less comprehensive estimates of the course of employment
and unemployment. Mr. Hornell Hart made an estimate of the
volume of unemployment by months during the period 1902 to
1917, inclusive;s Mr. Ralph D. Hurlin, of the Staff of the Russell
Sage Foundation utilized the Massachusetts data in constructing a
picture of “Three Decades of Employment Fluctuations”;” and
Professor William A. Berridge, in a series of valuable studies
presented in the Review of Economic Statistics and elsewhere,®
has analyzed the cyclical fluctuations in employment from 1903 to
date.
As employment is the primary measure of immigrant oppor-
tunity used in this study, and as it is desirable to carry our com-
parisons through as long a period as possible, it has seemed advisable
to prepare an index especially for our purposes rather than to rely
5s Federal Reserve Bulletin, Dec., 1923 (index of industrial employment); and Feb.,
1924 (“labor market” index).
sHornell Hart, Fluctuations in Unemployment in Cities of the United States, 1902-
1917, Studies from the Helen S. Trounstine Foundation, Vol. 1, No. 2, pp. 47-59.
"Ralph D. Hurlin, “Massachusetts Employment in Factories,” Annalist, Oct.
24, 1921, pp. 387-388.
Cf. articles in the Journal of the American Statistical Association, March, 1922, pp.
42-55, and June, 1922, pp. 227-240; the Review of Economic Statistics, January, 1922,
pp. 1-56; the Federal Reserve Bulletin, December 1923, pp. 1272-1279, and February,
OL En Sal also his volume entitled Cycles of Unemployment in the United States,
