Our population statistics cover age, sex, race, Hispanic origin, migration, ancestry, language use, veterans, as well as population estimates and projections.
The U.S. Census Bureau is the official source of statistical data tracking the national economy.
Business is a large part of America's diverse economy. This section provides key information about businesses in your community.
This section provides information on a range of educational topics, from educational attainment and school enrollment to school districts, costs and financing.
We measure the state of the nation's workforce, including employment and unemployment levels, weeks and hours worked, occupations, and commuting.
Our statistics highlight trends in household and family composition, describe characteristics of the residents of housing units, and show how they are related.
Health statistics on insurance coverage, disability, fertility and other health issues are increasingly important in measuring the nation's overall well-being.
We measure the housing and construction industry, track homeownership rates, and produce statistics on the physical and financial characteristics of our homes.
Income is the gauge many use to determine the well-being of the U.S. population. Survey and census questions cover poverty, income, and wealth.
The U.S. Census Bureau is the official source for U.S. export and import statistics and regulations governing the reporting of exports from the U.S.
The U.S. Census Bureau provides data for the Federal, state and local governments as well as voting, redistricting, apportionment and congressional affairs.
Geography is central to the work of the Bureau, providing the framework for survey design, sample selection, data collection, tabulation, and dissemination.
Find resources on how to use geographic data and products with statistical data, educational blog postings, and presentations.
The Geographic Support System Initiative will integrate improved address coverage, spatial feature updates, and enhanced quality assessment and measurement.
Work with interactive mapping tools from across the Census Bureau.
Find geographic data and products such as Shapefiles, KMLs, TIGERweb, boundary files, geographic relationship files, and reference and thematic maps.
Metropolitan and micropolitan areas are geographic entities used by Federal statistical agencies in collecting, tabulating, and publishing Federal statistics.
Find information about specific partnership programs and learn more about our partnerships with other organizations.
Definitions of geographic terms, why geographic areas are defined, and how the Census Bureau defines geographic areas.
We conduct research on geographic topics such as how to define geographic areas and how geography changes over time.
Official audio files from the Census Bureau, including "Profile America," a daily series of bite-sized statistics, placing current data in a historical context.
Read briefs and reports from Census Bureau experts.
Read research analyses from Census Bureau experts.
Find information using interactive applications to get statistics from multiple surveys.
Find a multitude of DVDs, CDs and publications in print by topic.
These external sites provide more data.
Download software to display, extract, map, process, and/or tabulate census and survey data.
Learn more about our data from this collection of e-tutorials, presentations, webinars and other training materials. Sign up for training sessions.
Learn more about our data from this collection of e-tutorials, presentations, webinars and other training materials. Sign up for training sessions.
Explore Census data with interactive visualizations covering a broad range of topics.
If you have received a survey, this site will help you verify that the survey came from us, understand and complete the form, and know how we protect your data.
This is the 2020 Census redirect
This is the 2020 Census redirect
National and state population totals from the 2010 Census were released on December 21, 2010
The American Community Survey (ACS) is a mandatory, ongoing statistical survey that samples a small percentage of the population every year.
The AHS is sponsored by the Department of Housing and Urban Development (HUD) and conducted by the U.S. Census Bureau.
The Economic Census is the U.S. government's official five-year measure of American business and the economy.
Collects data and measures change for many topics including: economic well-being, family dynamics, education, assets, health insurance, and childcare.
Most recent releases from the Newsroom.
Find media toolkits, advisories, and all the latest Census news.
The Census Bureau's Director writes on how we measure America's people, places and economy.
Find media toolkits, advisories, and all the latest Census news.
See what's coming up in releases and reports.
Find media toolkits, advisories, and all the latest Census news.
Access to embargoed releases for news and media outlets.
Information about the U.S. Census Bureau.
Information about what we do at the U.S. Census Bureau.
Our researchers explore innovative ways to conduct surveys, increase respondent participation, reduce costs, and improve accuracy.
The regional offices are responsible for all data collection, data dissemination, and geographic operations under a new service area boundary.
Learn about other opportunities to collaborate with us.
Explore the rich historical background of an organization with roots almost as old as the nation.
Explore prospective positions available at the U.S. Census Bureau.
The Census Bureau is hiring across the United States, search temporary positions
Learn about other opportunities to collaborate with us.
Newsroom Archive
Release Information
Contact: Public Information Office
301-763-3030
FOR IMMEDIATE RELEASE: TUESDAY, MAY 22, 2012
Census Bureau Releases Estimates of Undercount and Overcount in the 2010 Census
The U.S. Census Bureau released today results from its post-enumeration survey, providing a measure of the accuracy of the 2010 Census. The results found that the 2010 Census had a net overcount of 0.01 percent, meaning about 36,000 people were overcounted in the census. This sample-based result, however, was not statistically different from zero.
The post-enumeration survey, called “Census Coverage Measurement,” measures the coverage of the nation's household population (excluding the 8.0 million people in “group quarters,” such as nursing homes or college dorms). It surveys a sample of the 300.7 million people living in housing units and then matches the responses to the census, resulting in estimates of error.
The 2000 Census had an estimated net overcount of 0.49 percent and the 1990 Census had a net undercount of 1.61 percent.
“On this one evaluation — the net undercount of the total population — this was an outstanding census,” Census Bureau Director Robert Groves said. “When this fact is added to prior positive evaluations, the American public can be proud of the 2010 Census their participation made possible.”
Components of Coverage
The Census Bureau also released estimates of the components of coverage: the number of correct census records, erroneous enumerations and omissions.
The Census Bureau estimates that among the 300.7 million people who live in housing units, about 94.7 percent were counted correctly, about 3.3 percent were counted erroneously, 1.6 percent provided only a census count and had their demographic characteristics imputed, or statistically inserted, and 0.4 percent needed more extensive imputation after all census follow-up efforts were attempted. Among those erroneously counted, about 84.9 percent were duplicates, while the remainder were incorrectly counted for another reason, such as people who died before Census Day (April 1, 2010), who were born after Census Day or were fictitious census records.
The Census Bureau estimated 16.0 million omissions in the census. Omissions include people missed in the census and people whose census records could not be verified in the post-enumeration survey because they did not answer enough of the demographic characteristic questions in the census. Of the 16.0 million omissions, about 6.0 million were likely counted in the census but couldn't be verified in the post-enumeration survey.
Variation by Characteristics
As with previous censuses, the coverage of the population varied across demographic characteristics.
The 2010 Census undercounted renters by 1.1 percent, showing no significant change compared with 2000. Homeowners were overcounted in both the 2000 and 2010 censuses. However, the 2010 Census reduced the net overcount for homeowners from 1.2 percent to 0.6 percent. Renters were more likely to be duplicated than owners and twice as likely to have all of their characteristics imputed.
As with prior censuses, coverage varied by race and Hispanic origin. The 2010 Census overcounted the non-Hispanic white alone population by 0.8 percent, not statistically different from an overcount of 1.1 percent in 2000.
The 2010 Census undercounted 2.1 percent of the black population, which was not statistically different from a 1.8 percent undercount in 2000. In 2010, 1.5 percent of the Hispanic population was undercounted. In 2000, the estimated undercount of 0.7 percent was not statistically different from zero. The difference between the two censuses was also not statistically significant.
The Census Bureau did not measure a statistically significant undercount for the Asian or for the Native Hawaiian and Other Pacific Islander populations in 2010 (at 0.1 percent and 1.3 percent, respectively). These estimates were also not statistically different from the results measured in 2000 (a 0.8 percent overcount and a 2.1 percent undercount, respectively).
Coverage of the American Indian and Alaska Native population varied by geography. American Indians and Alaska Natives living on reservations were undercounted by 4.9 percent, compared with a 0.9 percent overcount in 2000. The net error for American Indians not living on reservations was not statistically different from zero in 2010 or 2000.
Men 18 to 29 and 30 to 49 were undercounted in 2010, while women 30 to 49 were overcounted, a pattern consistent with 2000. The estimated overcount of women 18 to 29 was not statistically significant.
“While the overall coverage of the census was exemplary, the traditional hard-to-count groups, like renters, were counted less well,” Groves said. “Because ethnic and racial minorities disproportionately live in hard-to-count circumstances, they too were undercounted relative to the majority population.”
Other Findings
- The post-enumeration survey did not measure a statistically significant undercount or overcount in the population or housing units for any state.
- The survey did not measure a statistically significant undercount or overcount for the population in any counties or places of 100,000 or more.
- The 2010 Census undercounted housing units, mostly because of an undercount of vacant units. On the other hand, there was no statistically significant undercount or overcount of occupied housing units.
- As a whole, erroneous enumerations and imputations were lower among people who mailed back a census form, compared with those counted by a door-to-door census taker. Additionally, responses mailed back earlier in the process were generally less likely to have erroneous enumerations than those mailed later.
- Among people counted door-to-door by a census taker, responses from a household member were more accurate than those from proxies, such as neighbors or landlords who provided information when a householder could not be reached or refused to participate in the census.
“We'll use these coverage estimates to build a better 2020 Census,” Groves said. “The 2010 Census used a variety of operations to improve coverage of the population. We now have measures of their success, which will inform cost-quality tradeoff decisions for the 2020 Census.”
The post-enumeration survey is one of three types of indicators that measure the quality of a census. The others consist of process indicators, which measure the quality of census operations and data collection, and comparisons to other methods of estimating population size. Each type of quality indicator has its own strengths and weaknesses as a measurement tool. For example, the estimates from the post-enumeration survey have sampling error and are susceptible to violations of the underlying statistical assumptions.