data method

The Census Bureau's Population and Housing Projections Program (PEP) data by county includes details such as counts by age, race, and ethnicity and goes back decades. However, the way the Census Bureau reports and groups these populations has changed over time.

lace category

Users will notice that the race categories change depending on the year they select in this interactive tool. This occurs because the Census Bureau has changed the racial and ethnic categories available. To enable comparisons over time, race categories change depending on the first year selected in the comparison tool.

If the earliest year selected in the tool is before 1990, the data includes only three racial categories: White, Black, and Other. As a result, comparisons that include data before 1990 include only these three race categories. Racial categories other than “Black” and “White” are included in the “Other” racial category for several years after 1990 when compared with pre-1990 data.

Comparisons where the first year is between 1990 and 1999 include two additional categories: “American Indian/Alaska Native” and “Asian or Pacific Islander.” Separate reports for “Asian” and “Native Hawaiian/Pacific Islander” are combined for years after his 2000, where the comparison year is his 1990s.

Data from 2000 considers “Asian” and “Native Hawaiian/Pacific Islander” as separate groups, and also includes a “multiracial” category. These categories do not exist for earlier years, so if a year before 2000 is selected, they will not appear in this tool's comparison. Prior to 2000, the Census Bureau did not separately identify people of two or more races. All people were grouped into a single racial category. In 2000, the Census added the category “two or more races” to its data. The Census Bureau estimates that this change will increase the number of people who were previously classified into a single racial category but who will now be classified into another racial category (i.e., “white,” “black,” etc.). He says he was influenced by. Two or more categories that have changed. Comparing pre-2000 and post-2000 data, the values ​​for separate racial categories are proportionally lower for the population of “two or more races.”

Ethnic category

In addition to changes in racial categories over time, starting in 1990, Hispanic ethnicity was also available at the county level. Hispanics can be of any ethnicity. Because it considers Hispanic people as a separate group, the tool above excludes Hispanic people from the racial category by default if both comparison years selected are after 1990. The resulting racial/ethnic comparison groups are Black, non-Hispanic, White, non-Hispanic, American Indian/Alaska Native, non-Hispanic, and Asian or Pacific Islander, non-Hispanic. “Hispanic”, “Hispanic”. ”. There is also an option for users to hide explicit Hispanic ethnicity and assign Hispanic people to designated racial categories.

Census reporting and update cycle

The Census Bureau annually releases preliminary population estimates based on the previous decennial census and other data on births, deaths, and immigration. Every 10 years, the Bureau adjusts these estimates and releases the final data.

These preliminary estimates are “post-census estimates,'' and the final estimates are “inter-census estimates.'' USAFacts used final pre-arrest estimates from 1970 to 2009 and provisional post-arrest estimates from 2010 onwards.

The most recent county-level data available by age, race, sex, and ethnicity are: Vintage 2020 Population Estimates (census.gov) From 2010 to 2019 Vintage 2022 Population Estimates (census.gov) We will update this experience to include estimates for 2010-2019 when the Bureau releases county-level 2010-2020 Intersensor estimates by age, sex, race, and ethnicity.

Care should be taken when interpreting population changes using different estimated vintages. It is known that post-arrest estimates from 2010 to 2020 underestimate the population nationally by about 1%. This underestimation was practically zero in 2010 and increases year by year until it reaches 1% by 2020. The estimated year is different from his decennial census of 2010, which is the basis. The undercount will be resolved in his 2023 when the Census Bureau releases estimates between his 2010 and his 2020 censuses.

Geography changes

In 2022, census bureau Accepted a new map for Connecticut's county equivalents to better reflect the state's actual governance system. As a result, a new map was created that divided the state into her nine counties, instead of her previous eight county map. This poses a major hurdle in providing context for changes in Connecticut's population over time. To address this concern, the Census Bureau has indicated that it plans to release alternative population estimates for Connecticut for the past five years using the most recent nine-county designations. USAFACTS plans to monitor these releases to determine whether these results can be combined with other data to provide a new county population change time series. While this was being determined, we inserted data from. Vintage 2021 Population Estimates (census.gov) We report on the state of Connecticut at the county level, following the old eight-county system to provide context over time. State and national numbers use 2022 vintage estimates, and we will continue to use the most recent state and national estimates even if we need to replace county-level data with older data. County-level data for Connecticut is limited to 2021 until additional data is available and evaluated.