The US Census

Unlike most surveys or studies that sample only a small portion of the total population, the U.S. Constitution mandates that the Census count every resident of the United States. The first census was taken in 1790; the 2010 Census was the nation’s 23rd. The 2010 Census counted over 300 million people and 115 million housing units. Information on most of these people and places was collected via census forms received by the Bureau within two weeks of Census Day, April 1, 2010. In 2010, the Census Bureau advertising campaign included a Superbowl ad and the sponsorship of a NASCAR race car to increase awareness and response rates (below are two posters from the marketing campaign). Despite the efforts, nearly a third of households still failed to return their forms. Door-to-door enumerators, working through the spring and summer of 2010, collected information about those who did not respond using the form.
The official purpose of the census is to determine the size of population for use in congressional district apportionment, but the significance of the data it collects extends far beyond a simple head count. It provides a ten-year “benchmark” for the nation’s population. Through the 2000 Census, a certain share of households (about 1-in-6 for the 2000 Census) received a longer form that included a larger battery of questions about the respondents’ social characteristics (e.g. education and English language proficiency), economic circumstances (e.g. occupation and labor force status), and housing situations. Although the “long-form” items were only asked to a portion of the total population, the sample was substantial enough to yield accurate estimates for population subgroups and smaller geographic areas. Since the 2010 Census, the “long form” is no longer used to collect this detailed information; instead, the annual American Community Survey (ACS), separate from the decennial census, has taken its place. The 2010 Census contained only a short, ten-question form. Thus data for the most recent year after 2000 is drawn from a recent American Community Survey.
The census distributes its results in the form of tables and computerized data files that are available in many formats. Published volumes are available for all U.S. censuses and can be found, for the most recent censuses, at most college, university and large public libraries. In the mid-1990s, the Census Bureau began an effort to make census tables and other information available electronically over the Internet. Today, almost all current census data are available for download from the website of the Census Bureau. For information regarding the release dates of data packages, visit the Census Bureau’s Census 2010 at a Glance webpage. While datasets including P.L. 94-171 and Summary File 1 containing basic demographic information have already been released, more detailed information is scheduled for release. The Census Bureau’s homepage includes a wealth of technical and historical information on the U.S. Census, as well as detailed reports on specific topics. From the main page, you can easily access the American FactFinder tool, which lets users download tables from the recent US Censuses using geographies ranging from the entire nation to counties to zip codes to census blocks. Finally, although the data are readily available in computerized format, many important resources are not. A good way to learn about the variety of census publications and other data products from the census would be to explore what is available at your college or university library. The best way to learn about the Census Bureau and the wide variety of products and services it offers, however, is to visit the Census Bureau website itself.