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National Scope SF3
ZIP Code Database

National Scope SF3
Census Tract Database
Census 2000 Data Access and Use
    Summary File 3
    -- an information resource developed and maintained by Warren Glimpse

Access the Summary File 3 data files via the general Census Webserver site:

All SF3 files for the U.S. are available as summarized at:

How to get the data fields you need from SF3 ... as described below, SF3 is structured as 77 separate data files for each state. A logical record key is required to relate data segments to each other. Almost everyone experiences time consuming problems in accessing the specific data fields required for analysis. Special software is required to perform the data extraction and integration in a time-efficient manner. See the graphic illustration of how the Proximity Census Data Integrator software can makes these data extraction and integration tasks much easier and faster.

Overview. The Census 2000 Summary File 3 (SF3) contains the data that are sample-based estimates based on the Census 2000 long-form questionnaire.

This page is a focus section on Summary File 3. The main Census 2000 Data Access and Use page is located at

Scheduled availability date: July-September 2002

Subject Matter. SF3 items include the following types of data.

Farm Residence
Grandparents as caregivers
Income in 1999
Labor force status
Language spoken at home
Marital Status
Migration (residence since 1995)
Place of birth, citizenship, year of entry
Place of work, journey to work
School enrollment and educational attainment
Veteran status
Heating Fuel
Number of rooms, number of bedrooms
Occupation, industry, class of worker
Plumbing and kitchen facilities
Telephone service
Units in structure
Utilities, mortgage, taxes, insurance, fuel costs
Value of home or monthly rent paid
Vehicles available
Work status in 1999
Year moved into residence
Year structure built

Files and File Structure. There are 76 data segments (compared to 39 for SF1). There are 16,516 subject matter fields, further categorized as follows:

•   12,238 population table items/fields
      - 8,082 PCT table items (census tract as low level geography)
      - 4,156 non-PCT table items (block group as low level geography)

•   4,278 housing table items/fields
      - 2,879 HCT table items (census tract as low level geography)
      - 1,399 non-HCT table items (block group as low level geography)

Subject Matter Descriptions. View subject matter/table descriptions here:

Access to Data -- Download SF3. Download SF3 data files from Census Web server here:

Summary File 3 Documentation. The Summary File 3 documentation is available in PDF format at this location:

Convert Summary File 3 ASCII to DBF. Using the Proximity ASC2DBF software Version 2, you can convert the Summary File 3 (SF3) ASCII data, downloaded free from the Census Web server, to dBase structure on your computer. Options include:
  1. select entire SF3 segments (corresponding to 76 data segments),
  2. select only individual data fields or tables that you need,
  3. select (using a button option) the "demographic profiles" data items, or
  4. convert the entire SF3 data for a state.
Option 2 enables you to quickly get just the data that you need for analyses.

Option 3 enables you to access the most widely used set of SF3 data.

Integrate Summary File 3 Data into Your Map Files. Using the Proximity Cen2Shp software, you will be able to automatically integrate ASC2DBF SF1 or SF3 dBASE files into shape file dbf's. Easy as 1-2-3 ...
  1. ASC2DBF conversion to SF3 dBASE file
  2. download free map files in shapefile format
  3. Use Cen2Shp to integrate the data in the SF3 dBASE file into the corresponding map shape file dbf (details explained in Cen2Shp documentation).
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National scope Summary File 3 Data by ZIP Code and Census Tract

Census 2000 Summary File 3 ZIP code and census tract files have been developed by Proximity for the U.S. Content, use, and benefits of these files/data are summarized below.

Two filesets have been prepared -- one for the U.S. by census tract and one for the U.S. by ZIP code (ZCTA). Each fileset contains three dBase files corresponding to three demographic profile tables further described below.

Why use these data?. These files contain data for individual census tracts and ZIP code areas across the state. Data for census tracts are used for funding and qualification criteria by many governmental programs. These files provide a way to examine characteristics of individual census tracts but more importantly in the context of all other census tracts. Since the most common small area data from non-census sources is data summarized by ZIP code, ZIP code demographics are useful in many applications.

  • Compare neighborhood characteristics using a composite set of key indicators.
  • Assess 'state of education' -- educational attainment on a small area basis.
  • Determine propensity to vote a certain way on a certain issue.
  • Analyze attributes of the housing market.
  • Assess size of medically underserved population.
  • Examine patterns of labor force/employment infrastructure.
  • Assess the need/demand for wide-ranging products and services.
  • Analyze number of children in school for health related programs.

Enhancing Value. These data may be used to analyze poverty incidence by census tract or ZIP code. As the data are in a data file, non-census data may be added to the data records.

Subject Matter. Subject matter items included are summarized in the these demographic profile table descriptions:

  • DP2 -- Social Characteristics
  • DP3 -- Economic Characteristics
  • DP4 -- Housing Characteristics

These subject matter items are the same as used to produce the Waimanalo CDP and Hawaii demographic profiles (different geography and in Excel format) and available from Proximity for any place, county, or state in the U.S. The subject matter items are also described in the demographic profile technical documentation. The technical documentation provides a further description of each of the subject matter items using the same variable/item name as used in the dBase files.

DP1 Data from SF1. The DP1, General Demographics, data file is also available These data are derived from Summary File 1. The geographic fields in the data record are a little differently structured than for the DP2, DP3, and DP4 files. Also note that this version of DP1 has a larger number and differently named fields than conveyed by the technical documentation. The additional fields are the number of persons by single year of age, ages less than 1 year through 19 years, by gender. Refer to the DP1 items description for the item description and associated variable names used in the file.

Geography. Data records correspond to individual census tracts in the census tract fileset and 5-digit ZCTAs in the ZCTA fileset. Each data record in the DP2 - DP4 files carries the same set of geographic identifier codes. These 83 fields are the same geographic fields as contained in the corresponding Summary File 3 geographic data segment. Documentation for the geographic code (and related) fields is located in the Summary File 3 technical documentation. The geographic identifier codes differ slightly in the DP1 files.

Files for the State of Hawaii. Files for the State of Hawaii are available on a no-fee basis for downloading for use in non-income producing and non-funded research applications. Other users may purchase the files for Hawaii, any state, or the U.S. (inquire here).

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