The statistics corner: more new products from the Census Bureau

Business Economics, Oct, 1991 by John Ostenso

THE 1990 CENSUS will provide this century's single best "portrait" of our Nation's people and housing. The first block-level data were released in March 1991. By the end of 1993, the 1990 product "line" will grow to include 500,000 published pages and some 85 billion data cells. The data are being used to reapportion the 103rd Congress, distribute some $120 billion in Federal assistance each year, and support countless business decisions.

The volume and diversity of census data can be overwhelming. To help users understand the census data products, this article highlights 1990 changes, discusses major products, and outlines new geographic information.

CHANGES FOR 1990

Data content and products for the 1990 census will be very similar to their 1980 counterparts. Census data collection methods were improved but not fundamentally changed. Data processing operations were reorganized and more automated. However, these processing changes are largely "invisible" to census participants and data users.

Users of previous decennial census data may note three types of changes in 1990 data products: revised content, new products, and earlier release. These changes are modest compared to those in 1980, but may be important for those with specific subject or product interests.

Revised content. Dozens of revisions were made in the 1990 short and long form questions. Many were technical in nature, such as adding categories for higher property values and new racial and ethnic information, and dropping month of birth. Other changes were more substantive. For example, adding categories for household living arrangements, difficulties faced by the disabled, condominium fees, pension income, and for-profit versus not-for-profit employers.

In addition, concern for respondent burden and changing data priorities resulted in some questionnaire deletions. Questions not retained for 1990 included marital history, parochial school attendance, carpooling arrangements, and several housing questions (number of floors, living units and bathrooms; type of heating system; air conditioning; elevator; and water heating and cooking fuels).

New Products. The 1990 census was the first to offer data on compact disc-read only memory (CD-ROM) and on-line formats for use with personal computers. The first CD-ROMs were released in early 1991, providing redistricting counts for states, counties and areas as small as a single block. Future discs will provide additional population and housing statistics, and include data for ZIP Codes.

The Census Bureau's on-line data service is CENDATA, available through commercial vendors. CENDATA carries up-to-the-day product information and summary statistics from many 1990 products. For example, CENDATA carried the press release text and redistricting counts for each state, but the companion state CD-ROM included counts for all geographic levels down to the block level.

Earlier release. The Census Bureau responded to user requests for earlier release of census data through faster production, restructed content, and other product changes. Examples of faster production include issuing the first redistricting file three weeks earlier than in 1980 and with data items not previously included, and releasing the first complete 1990 short-form data on computer tapes nine months earlier than in 1980 and with expanded content.

In addition, structural changes included holding metropolitan and urbanized-area data for later reports, and eliminating Summary Tape File 5 (STF 5) but incorporating key data items into an expanded program of subject reports. Other changes for 1990 include eliminating all preliminary reports, rearranging selected geographic areas in printed reports, and reducing the amount of historical data presented in early reports.

MAJOR DATA PRODUCTS

The 1990 products reflect eight broad data concepts. For each concept, data on computer tapes are the earliest and most detailed product. Some eight weeks after tapes are released, the same or similar data will routinely appear in printed reports, CD-ROM and microfiche.

The sequencing of 1990 data products reflects data source,and geographic area, and subject matter detail. Products based on short-form (100-percent) data precede long-form (17-percent sample) products, general-purpose products come before specialized ones, and U.S. summary data are last in a series. Major 1990 data product concepts are discussed below in approximate order of initial release.

Apportionment and redistricting counts. The reapportionment press release included short-form population counts, and redistricting data include selected population and housing counts for small areas (including voting districts where states identified them). The redistricting file included age-eighteen detail and nationwide block coverage not previously available.

Reapportionment counts by state were released in December 1990. Computer tapes with redistricting data are called the P.L. 94-171 File. These data are also available on compact disc and as hard-copy printouts. Release of the P.L. 94-171 File by state, along with accompanying maps, was completed in March 1991.