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. For more information, visit the IPUMS USA Web site. |
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