Summary: | In addition to the historic Census files, 1790-1950,
ICPSR archives and distributes Census data acquired from the United
States Census Bureau as well as files prepared by ICPSR and other
principal investigators for the decennial years 1960, 1970, 1980, 1990,
and 2000. These include major sets such as the Summary Tape/Count Files,
Master Enumeration District List (MEDList) files, and Public Use
Microdata Samples (PUMS), as well as various subsets. ICPSR distributes
all data files prepared for the 1980 Census of Population and Housing
in accordance with Public Law 94-171 (the reapportionment files), as
well as all Public Use Microdata Samples (PUMS) files and all files
in the Summary Tape File 1 (STF 1) and Summary Tape File 3 (STF 3)
series. ICPSR also distributes many of the files from STF 2 and STF 4.
Summary Tape Files (STFs) vary by summary level of geography, detail
of information, and whether 100 percent or sample. STF 1 and 2 provide
100-percent data and are based on the set of census questions answered
for all persons and housing units. STF 3, 4, and 5 are based on sample
data derived from the responses of a sample of the population and
housing units and contain more extensive housing and socioeconomic
information. In addition, several special tabulations based on the
1980 Census are available, including the Equal Employment Opportunity
Special File; Journey-to-Work; Congressional District Equivalency
File (99th Congress); County Migration by Selected Characteristics;
County Population by Age, Sex, Race, and Spanish Origin; County and
MCD by ZIP Code; Person and Housing Unit Counts for Tracts and Minor
Civil Divisions; and Extract Data. Master Area Reference Files (MARFs)
1, 2, 3, and 5 and several 1980 Census extracts are available as well.
MARFs link geographic areas with their respective numeric codes and
indicate the relationships among the various areas recognized. They
are also abbreviated summary files containing selected population
and housing unit counts which can be used for the preparation of
sampling frames or for analyzing the content and scope of data to
be presented on STF1 and STF2. Public Use Microdata Samples (PUMS)
were created by the Census Bureau since 1960 as part of each
decennial enumeration. Public Use Microdata Samples (PUMS) for
the 1980 Census contain individual- and household-level
information from the long-form questionnaires distributed to a
sample of the population enumerated in the Census. PUMS make
it possible for researchers to create tabulations tailored to
their particular questions and to make time-series comparisons.
Three different PUMS series were prepared in 1980, each
containing a number of discrete physical files. These series are
called the A Sample, the B Sample, and the C Sample. The A sample
represents the state, the B sample represents the metro areas,
and the C sample represents the urban/rural areas. The state (A)
sample identifies all states, larger metropolitan areas, and most
counties over 100,000 population. In many cases, individual
cities are also identified. The state sample is very large,
including 1-in-20 (5 percent) of the United States population.
Only 20 states can be completely identified, because metropolitan
areas frequently cross state boundaries and identification of
both state and metropolitan area would violate the confidentiality
rules. The metro (B) sample identifies 282 metropolitan areas
over 100,000 population. Metropolitan areas are distinguished from
non-metropolitan areas, but the sample does not identify
urban/rural residence. The urban/rural (C) sample identifies
urban/rural residence, central city residence, and particular
urbanized areas. Because of confidentiality reasons, the samples
do not identify any places smaller than 100,000 inhabitants. |
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