What data does the 2020 Census cover?
The 2020 Census covers a broad range of demographic information with just seven key questions:
- Number of people living in a household
- Relationship among people living in a household
- Housing tenure (owned or rented)
- Gender of people in the household
- Age of people in the household
- Ethnicity (Hispanic or non-Hispanic) of people in the household
- Race of people in the household
The data can be combined to provide multiple insights, such as the number of non-Hispanic Black children in a specific area or the percentage of Native American homeowners in a given location.
How does the 2020 Decennial Census differ from the American Community Survey (ACS)?
The American Community Survey (ACS) is an ongoing effort that collects data on demographic, social, economic, health, and education characteristics of the U.S. population. The Census Bureau distributes surveys to a random sample of U.S. addresses every month, with each household having a roughly 1-in-480 chance of being selected every five years.
The ACS is generally released in two phases:
- A single-year sample for the previous year, which includes detailed data for larger geographies (states, most U.S. counties, metro areas, and places with more than 65,000 people). This is typically released in September.
- A five-year sample, released in December, which includes detailed data for smaller geographies, usually down to the census tract level.
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Note: Due to the COVID-19 pandemic, a single-year sample was not released in 2021. |
How does the 2020 Census differ from previous censuses?
The 2020 Census maintained consistency with previous censuses but introduced some changes:
- It included space for Black and white respondents to describe their race in more detail (e.g., Caribbean, Irish, etc.).
- It implemented differential privacy, a method designed to enhance data security by slightly altering reported data, which has raised concerns about demographic accuracy.
Historically, census categories have evolved. For example, the first U.S. Census in 1790 had racial categories limited to "white" and "non-white," with distinctions for enslaved individuals. Over time, more racial and ethnic categories have been introduced.
How is the Census used?
The Census serves three primary purposes:
- Redistricting: It helps establish fair voting district boundaries in compliance with federal representation laws.
- Survey Foundations: The data serves as a population base for the American Community Survey, ensuring an accurate demographic representation.
- Federal Funding Allocation: Census data directs trillions of federal dollars toward programs such as Medicare, Head Start, and food assistance programs over the next decade.
What is included in the data and why?
The Census primarily counts populations within each state to determine congressional representation. Over time, its use has expanded to ensure fair voting district representation under laws such as the Civil Rights Act of 1964 and the Voting Rights Act of 1965.
Additionally, the Census serves as the base for the American Community Survey, which guides federal funding distribution for critical services.
What is not included in the data and why?
The Census does not ask about:
- Religious preference
- Political affiliation
- Gun ownership
- Citizenship status
- Personal financial details
All Census questions are approved by Congress, meaning controversial topics such as political or religious affiliation are unlikely to be included. In 2020, an attempt to add a citizenship question was blocked through legal challenges.
What geographies are available in the 2020 Census dataset?
The Census data is organized by multiple geographical units, including:
- Census Blocks (more than 10 million)
- Census Tracts (roughly 80,000, representing neighborhoods)
- Places (30,000+ cities and towns, including Census Designated Places)
- Counties (3,100+ counties and equivalents)
- States (50 states, plus U.S. territories and Washington, D.C.)
Additional geographical units include county subdivisions, metropolitan/micropolitan areas, legislative districts, school districts, and Native American lands.
What issues may arise from the data?
One significant concern with the 2020 Census is differential privacy, which shifts population data to protect individual identities. While intended to enhance privacy, this method may introduce inaccuracies, such as:
- Neighborhoods appearing to be populated only by children
- Areas with no racial or ethnic diversity
- Demographic distortions that may impact redistricting
Additionally, the 2020 Census had one of the lowest response rates in modern history, with notable increases in missing data:
- 5.95% of households did not report birth dates
- 5.35% did not indicate Hispanic ethnicity
- 5.77% did not report racial identity
These nonresponse rates were significantly higher than those from 2010, raising concerns about data completeness.
What is unique about the 2020 Census?
- First Census to allow responses online and by telephone
- Conducted during the COVID-19 pandemic
- Allowed white and Black respondents to specify racial backgrounds for the first time
- Consolidated PL94-171 redistricting data into a single release
What makes Social Explorer’s Census data unique?
Social Explorer is the only data provider that allows users to compare the 2010 and 2020 Census results at all geographic levels, including over 11 million census blocks.
However, two key considerations must be noted:
- Geographic boundary changes: Over time, place and county boundaries shift due to annexation, remapping, or renaming. Social Explorer adjusts data accordingly.
- Disclosure Avoidance System (DAS): To protect privacy, the Census Bureau slightly shifts individual data within small geographies, which can result in inconsistencies at the block, block group, or tract level. Social Explorer advises caution when making comparisons at these small geographic levels.