3 and 4. Decennial Censuses.
5. For all years except 1975-Decennial Censuses. For 1975-Current Population Survey.
Current Population Reports, Series P-25, No. 614. For 1975
estimates-U.S. Bureau of the Census, Current Population
Reports, Series P.)
and 2000-U.S.
Reports, Series P
For 1980, 1985, 1990, 1995,
Current Population
10. For all yo 1975-unpublishe population.
11. For all 1975-U.S. Bure
ports, Series P-2
SOURCE AND RELIABILITY OF THE DATA
Source of Data
Most of the estimates in this report are based on data ob
tained from the Current Population Survey and Decennial
Censuses conducted by the Bureau of the Census. Other
data were provided by private concerns and various govern
mental agencies including the Bureau of Labor Statistics,
National Center for Health Statistics, and the Department of
Defense. A complete list of sources is shown in Appendix A,
"References for Tables."
Current Population Survey (CPS). The monthly CPS deals
mainly with labor force data for the civilian noninstitutional
population. Questions relating to labor force participation
are asked every month about each member 14 years old and
older in each sample household. In addition, supplementary
Another modification affects CPS data from March
1973 through March 1978. Starting in January 1972, 1970
census-based population controls, metropolitan residence
definitions, and other materials were introduced into the
sampling and estimation procedures. The major item affecting
comparability at the national level is the introduction of
population controls based on the 1970 census. Figures for
previous ves
where noted, are tied in with
controls. Basically, these changes
ct on summary measures, such as
on proportional measures, such as
ever, the changes may have more
evels in different subgroupings or
egory. Specific instances in the
otnoted accordingly. A detailed
appears in the Bureau of Labor
1t and Earnings, Vol. 18, No. 8.
PS, beginning December 1971,
ata only, is the inclusion of a
st were your most important
rovided additional information
ipation. Additionally, changes
ion for the 1970 Census of
in the Current Population
further explanation of these
sus, Technical Paper No. 26,
y Classification Systems in
n and Industry Elements,"
Employment and Earnings,
No. 8.
questions are asked in most months about various population
characteristics.
The present CPS sample was initially selected from the
1970 census file and is updated continuously to reflect new
construction where possible (see section, "Nonsampling
Variability," below). The monthly CPS sample is spread over
461 areas with coverage in each of the 50 States and the
District of Columbia. A supplementary sample of housing
units in 24 States and the District of Columbia was incor
porated with the monthly CPS sample to produce the 1977
and 1978 data. The expanded CPS sample is located in 614
areas comprising 1,113 counties, independent cities, and
divisions in the Nation. The 614 sample areas used include
461 areas from the monthly CPS and 153 supplementary
Description of the Current Population Survey
from the U.S. Department e, are from actual death ths in the United States. registration States only. 1900, 10 States reported.
ted since 1915. At that area included 10 States 1933, the birth registra
re United States, with
nd Hawaii beginning in
were the result of a
by the Public Health
based on a 50-percent
for 1955 when they
967 when they were