U.S. Census Bureau Delivers Data for States to Begin Redistricting Efforts
The U.S. Census Bureau today released additional 2020 Census results showing an increase in the population of U.S. metro areas compared to a decade ago. In addition, these once-a-decade results showed the nation’s diversity in how people identify their race and ethnicity.
“We are excited to reach this milestone of delivering the first detailed statistics from the 2020 Census,” said acting Census Bureau Director Ron Jarmin. “We appreciate the public’s patience as Census Bureau staff worked diligently to process these data and ensure it meets our quality standards.”
These statistics, which come from the 2020 Census Redistricting Data (Public Law 94-171) Summary File, provide the first look at populations for small areas and include information on Hispanic origin, race, age 18 and over, housing occupancy and group quarters. They represent where people were living as of April 1, 2020, and are available for the nation, states and communities down to the block level.
The Census Bureau also released data visualizations, America Counts stories, and videos to help illustrate and explain these data. These resources are available on the 2020 Census results page. Advanced users can access these data on the FTP site.
Today’s release reveals changes in the size and distribution of the population across the United States. The population of U.S. metro areas grew by 9% from 2010 to 2020, resulting in 86% of the population living in U.S. metro areas in 2020, compared to 85% in 2010.
“Many counties within metro areas saw growth, especially those in the south and west. However, as we’ve been seeing in our annual population estimates, our nation is growing slower than it used to,” said Marc Perry, a senior demographer at the Census Bureau. “This decline is evident at the local level where around 52% of the counties in the United States saw their 2020 Census populations decrease from their 2010 Census populations.”
County and metro area highlights:
A data visualization released today shows the population change at the county level from the 2010 Census to the 2020 Census. Read more about population change in the America Counts story, More Than Half of U.S. Counties Were Smaller in 2020 Than in 2010.
The 2020 Census used the required two separate questions (one for Hispanic or Latino origin and one for race) to collect the races and ethnicities of the U.S. population — following the standards set by the U.S. Office of Management and Budget (OMB) in 1997. Building upon our research over the past decade, we improved the two separate questions design and updated our data processing and coding procedures for the 2020 Census. This work began in 2015 with research and testing centered on findings from the 2015 National Content Test, and the designs were implemented in the 2018 Census Test.
The improvements and changes enabled a more thorough and accurate depiction of how people self-identify, yielding a more accurate portrait of how people report their Hispanic origin and race within the context of a two-question format. These changes reveal that the U.S. population is much more multiracial and more diverse than what we measured in the past.
We are confident that differences in the overall racial distributions are largely due to improvements in the design of the two separate questions for race data collection and processing, as well as some demographic changes over the past 10 years.
Today’s release of 2020 Census redistricting data provides a new snapshot of the racial and ethnic composition of the country as a result of improvements in the design of the race and ethnicity questions, processing and coding.
“As the country has grown, we have continued to evolve in how we measure the race and ethnicity of the people who live here,” said Nicholas Jones, director and senior advisor for race and ethnicity research and outreach at the Census Bureau. “Today’s release of 2020 Census redistricting data provides a new snapshot of the racial and ethnic composition and diversity of the country. The improvements we made to the 2020 Census yield a more accurate portrait of how people self-identify in response to two separate questions on Hispanic origin and race, revealing that the U.S. population is much more multiracial and more diverse than what we measured in the past.”
Race and ethnicity highlights:
It is important to note that these data comparisons between the 2020 Census and 2010 Census race data should be made with caution, taking into account the improvements we have made to the Hispanic origin and race questions and the ways we code what people tell us.
Accordingly, data from the 2020 Census show different but reasonable and expected distributions from the 2010 Census for the White alone population, the Some Other Race alone or in combination population, and the Multiracial population, especially for people who self-identify as both White and Some Other Race.
These results are not surprising as they align with Census Bureau expert research and corresponding findings this past decade, particularly with the results on the impacts of questions format on race and ethnicity reporting from the 2015 National Content Test.
The Census Bureau uses several measures to analyze the racial and ethnic diversity of the country.
The Census Bureau uses the Diversity Index (DI) to measure the probability that two people chosen at random will be from different racial and ethnic groups.
The DI is bounded between 0 and 1. A value of 0 indicates that everyone in the population has the same racial and ethnic characteristics. A value close to 1 indicates that almost everyone in the population has different racial and ethnic characteristics.
We have converted the probabilities into percentages to make them easier to interpret. In this format, the DI tells us the chance that two people chosen at random will be from different racial and ethnic groups.
Using the same DI calculation for 2020 and 2010 redistricting data, the chance that two people chosen at random will be from different racial or ethnic groups has increased to 61.1% in 2020 from 54.9% in 2010.
In general, the states with the highest DI scores are found in the West (Hawaii, California and Nevada), the South (Maryland and Texas; along with the District of Columbia, a state equivalent), and the Northeast (New York and New Jersey).
Hawaii had the highest DI score in 2020 at 76%, which was slightly higher than 2010 (75.1%).
Information on the racial and ethnic composition of your state and county, and various measures of diversity are available in the following America Counts stories: 2020 U.S. Population More Racially and Ethnically Diverse Than Measured in 2010 and Improved Race and Ethnicity Measures Reveal U.S. Population Is Much More Multiracial.
The 2020 Census showed that the adult (age 18 and older) population group grew 10.1% to 258.3 million people over the decade.
“More than three-quarters, 77.9%, of the U.S. population were age 18 and over,” said Andrew Roberts, chief of the Sex and Age Statistics Branch in the Census Bureau’s Population Division. “The adult population grew faster than the nation as a whole. By comparison, the population under age 18 was 73.1 million in 2020, a decline of 1.4% from the 2010 Census.”
Changes to the adult and under-age-18 populations:
Additional age breakdowns will be available in future 2020 Census data releases scheduled for 2022.
As part of today’s release, the Census Bureau provided a new data visualization that highlights the adult and under-age-18 populations across the United States down to the county level. More information is available in the America Counts story, U.S. Adult Population Grew Faster Than Nation’s Total Population From 2010 to 2020.
The 2020 Census showed that on April 1, 2020, there were 140,498,736 housing units in the United States, up 6.7% from the 2010 Census.
“While the national number of housing units grew over the past decade, this was not uniform throughout the country,” said Evan Brassell, chief of the Housing Statistics Branch in the Census Bureau’s Social, Economic and Housing Statistics Division. “Counties that composed some part of a metropolitan or micropolitan area saw increases of 3.8%, on average, while counties outside of these areas showed decreases of 3.9% on average.”
Housing unit statistics for the nation, states and counties are available in the 2020 Population and Housing data visualization. More information is available in the following America Counts stories: Growth in Housing Units Slowed in the Last Decade and U.S. Housing Vacancy Rate Declined in Past Decade.
The U.S. population for group quarters was 8,239,016 as of April 1, 2020. This was an increase of 3.2% over the 2010 Census group quarters population. Group quarters include such places as college residence halls, residential treatment centers, skilled-nursing facilities, group homes, military barracks, correctional facilities, and workers’ dormitories.
“In 2020, the group quarters population represented 2.5% of the total U.S. population, down from 2.6% in 2010,” said Steven Wilson, chief of the Population and Housing Programs Branch in the Census Bureau’s Population Division. “We also saw that college and university student housing was the most populous group living arrangement at 2,792,097, up 10.7% since 2010.”
Group quarters highlights:
Read more about these results in the America Counts story, 8.2 Million People Counted at U.S. Group Quarters in the 2020 Census. You can also access more statistics in the 2020 Census Demographic Data Map Application.
All indications show the census results are in line with expectations.
“We are confident in the quality of today’s results,” said acting Census Bureau Director Ron Jarmin.
In keeping with our commitment to transparency, the Census Bureau will release additional operational quality metrics on August 18 and August 25, providing more detail on the conduct of specific operations.
The redistricting data are the first from the 2020 Census to use differential privacy, a mathematical method that applies carefully calibrated statistical noise to a dataset and allows a balance between privacy and accuracy. More information is available in 2020 Census Data Products: Disclosure Avoidance Modernization and Redistricting Data: What to Expect and When.
In addition to the redistricting data released today, the Census Bureau has released a set of demonstration data that illustrate the impact of the differential privacy production settings on published 2010 Census redistricting data. The Census Bureau released similar demonstration datasets over the course of the new method’s development.
These data released today are in the same format that the 2000 and 2010 redistricting data were provided. The term “legacy” refers to its prior use. By September 30, we will release these same data to state officials with an easy-to-use toolkit of DVDs and flash drives and we will make it available to the public on data.census.gov. The Census Bureau will notify the public in September when it makes these same data available.
Data are available in the 2020 Census Demographic Data Map Application through different data visualizations and QuickFacts. Data files are also available on the Decennial Census P.L. 94-171 Redistricting Data Summary Files page and includes the geographic support files, technical documentation and additional support materials needed to access these data.
The Census Bureau has also produced a variety of America Counts stories on population change and distribution, group quarters, the adult population, housing changes, housing vacancy, race and ethnicity and the diversity index. Videos are also available that explain how to access these data and what these data show about the changing nation.