DOI: 10.3886/icpsr13576.v1
title: Census of Population and Housing, 2000 [United States]: Block Group Subset From Summary File 3
title: Version 1

description: Prepared by the Inter-university Consortium for Political
 and Social Research, the block group subset was extracted from the
 Census of Population and Housing, 2000, Summary File 3 (SF3). The SF3
 data contain information compiled from the questions asked of a sample
 of persons and housing units enumerated in Census 2000. Population
 items include sex, age, race, Hispanic or Latino origin, household
 relationship, marital status, caregiving by grandparents, language and
 ability to speak English, ancestry, place of birth, citizenship status
 and year of entry to the United States, migration, place of work,
 journey to work, school enrollment, educational attainment, veteran
 status, disability, employment status, industry, occupation, class of
 worker, income, and poverty status. Housing items include housing unit
 vacancy status, housing unit tenure (owner/renter), number of rooms,
 number of bedrooms, year moved into unit, occupants per room, units in
 structure, year structure built, heating fuel, telephone service,
 plumbing and kitchen facilities, vehicles available, value of home,
 rent, and shelter costs. The information in SF3 is presented in 813
 tables, one variable per table cell, plus additional variables with
 geographic information. However, only 409 of these tables are shown
 for the block group and higher levels of geography. The remaining 404
 tables, which are shown for the census tract and higher levels of
 geography, were excluded from the block group subset. Cases in the
 summary file data are classified by levels of observation, known as
 "summary levels" in the Census Bureau's nomenclature. The block group
 subset comprises all of the cases in the SF3 data for summary level
 150. Five data files are provided with this collection. There is a
 block group subset for each of the four census regions (Northeast,
 Midwest, South, and West), plus a national subset that covers all of
the regions.
description: Every person and housing unit in the United States was
 asked basic demographic and housing questions, for example, race, age,
 relationship to householder, housing unit vacancy status, and housing
 unit tenure. A sample of these people were asked more detailed
 questions about items such as income, occupation, and housing costs.
 The sampling unit for Census 2000 was the housing unit, including all
 occupants. There were four different housing unit sampling rates:
 1-in-8, 1-in-6, 1-in-4, and 1-in-2 (designed for an overall average of
 about 1-in-6). The Census Bureau assigned these varying rates based on
 pre-census occupied housing unit estimates of various geographic and
 statistical entities, such as incorporated places and interim census
 tracts. For people living in group quarters or enumerated at long-form
 eligible service sites (shelters and soup kitchens), the sampling unit
was the person and the sampling rate was 1-in-6.
description: Datasets: 
DS0: Study-Level Files
DS1: All Regions
DS2: Northeast Only
DS3: Midwest Only
DS4: South Only
DS5: West Only
description: All persons and housing units in the United States.
description: (1) The original SF3 data comprise 4,081 files. For
 the nation as a whole, every state, the District of Columbia, and
 Puerto Rico, there is one column-delimited file that contains
 geographic identifiers (the geographic header record file or "Geo"
 file), plus 76 comma-delimited table files, each of which contains a
 portion of the SF3 tables. For states, the District of Columbia, and
 Puerto Rico, the variables in the Geo file and table files 1-18 and
 56-62 are shown down to the block group level, but the variables in
 table files 19-55 and 63-76 are only shown down to the census tract
 level. Consequently, table files 19-55 and 63-76 have fewer records
 than the Geo file and table files 1-18 and 56-62. In comparison, every
 one of 77 national files has the same number of cases. (2) The block
 group subset was produced one state at a time from the 4,004 state
 files (including the District of Columbia and Puerto Rico). Initial
 steps in the production of a subset for a state involved sorting its
 Geo file and table files 1-18 and 56-62 in ascending order of the
 common identification variable LOGRECNO, reformatting the Geo file as
 a comma-delimited file, and stripping off the first five
 identification variables from table files 1-18 and 56-62. Next, the
 reformatted Geo file was merged with the stripped table files so that
 corresponding records in the Geo and table files were joined as a
 single record in the merged file. A state subset was generated by
 extracting from the merged file all cases coded 150 for SUMLEV, the
 variable that identifies the summary level. After subsets were
 produced for every state, the national and regional subsets were
 generated by combining their component state subsets in ascending
 order of their state Federal Information Processing Standards (FIPS)
 codes. (3) The following states are included in the regional files.
 Northeast: Connecticut, Massachusetts, Maine, New Hampshire, New
 Jersey, New York, Pennsylvania, Rhode Island, and Vermont. Midwest:
 Iowa, Illinois, Indiana, Kansas, Michigan, Minnesota, Missouri, North
 Dakota, Nebraska, Ohio, South Dakota, and Wisconsin. South: Alabama,
 Arkansas, District of Columbia, Delaware, Florida, Georgia, Kentucky,
 Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South
 Carolina, Tennessee, Texas, Virginia, West Virginia, and Puerto
 Rico. West: Alaska, Arizona, California, Colorado, Hawaii, Idaho,
 Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming.
 (4) The implied decimal places in variables INTPTLAT (latitude) and
 INTPTLON (longitude) in the original data files were made explicit in
 the subset files. Additionally, the values of all the Geo variables
 were enclosed in quotes in the subsets, except for variables AREALAND,
 AREAWATR, POP100, HU100, INTPTLAT, and INTPTLON. (5) The data
 definition statements were tested with SAS 8, SPSS 10, and Stata/SE
 8. (6) The codebook documents data collection procedures, concepts,
 and individual variables in the original Summary File data as well as
 the ICPSR-produced subset files, but not the layout and structure of
 the subsets. That information is contained in the data dictionary file
 provided with this collection. (7) The codebook is provided by the
 principal investigators as a Portable Document Format (PDF) file. The
 PDF file format was developed by Adobe Systems Incorporated and can be
 accessed using PDF reader software, such as the Adobe Acrobat
 Reader. Information on how to obtain a copy of the Acrobat Reader is
provided on the ICPSR Web site.