Tag Archives: voting age

Single Year of Age Demographics

Single year of age (SYOA) demographics are demographic data summarized for the single year of age population (e.g., age 1, age 2, etc.) for a geographic area such as a county, census tract or ZIP code area. This section is part one of three sections and is focused on tools and methods to access, integrate and analyze SYOA data. The second part is focused on integrating these data with other data and use of GIS and geospatial analysis. The third part reviews how these data are used to develop projections and access to/use of projections.  See more details in related Web section

Population Age 0 Relative to 1,000 Population by ZIP Code
  — Atlanta Metro


– Crude birth rate approximation: population age 0 relative to 1,000 population
– Darker green: rate 16+; medium green: rate 12-16; light green: less than 12
– Click graphic for larger view, zoom-in, labeled with ZIP codes and rate.
– View developed with CV XE GIS.

Using SYOA Demographics
Except for possibly the single year of age 0, less than one year of age, single year of age demographics are intrinsically not in high demand. The fact that the single year of age demographics can be aggregated to standardized age cohorts and custom age groups is another matter entirely. Analysts and researchers often need current estimates or projections for age-gender-race/origin groups that are not available from pre-planned tabulations.

Uses of these SYOA data include the basics of understanding the size of a specific age group relative to the total population. Or, how the size of a total population age group compares among genders or a specific race/origin. There are a myriad of more focused applications such as estimating voter propensities/outcomes for certain combinations of age by gender by race/origin combinations. What single year of age data are available and how can they be used to meet these needs?

SYOA Data Options
The only Census Bureau-sourced option for SYOA county or sub-county geography data from Census 2010 forward is Census 2010. Age-related data from the American Community Survey (ACS) exist only for age groups (other than a few selected single year tabulations). Age-related data from the Census Bureau model-based annual estimates (county-up) are only available at the 5-year age cohort level. Most SYOA data (covering each age to age 99 and 100 and over) are further broken out only by gender and race/origin. That is, there are no SYOA summary data for other attributes such as foreign born for each/all ages. Census 2010 and ACS Public Use Microdata Sample data can be used to tabulate/estimate SYOA data with extended attributes though 1) such estimates can only be developed for areas 100,000 population or more and 2) the thinness of number of cases generally makes this infeasible.

The National Center for Health Statistics (NCHS/NVSS) provides SYOA data for county geography. These data are controlled to Census Bureau annual model-based estimates (not released by Census). The NCHS “bridge estimates” data are available annually 2010 forward (2013 estimates available as of March 2015). See more information.

ProximityOne provides census tract, ZIP code area and county-up geography SYOA estimates and projections to 2020. See more information about 5-year projections and projections to 2060.

Census 2010 SYOA
The Census-sourced single year of age demographics for sub-county areas are from the Census 2010 Summary File 1 (SF1). The Census 2010 SF1 “PCT012” (PCT: Population Census Tract and higher geography) tables provide single year of age by gender by race/origin population data for U.S. national scope census tract, ZIP code area and higher level geography. See more about the content and structure of the PCT012 tables.

SYOA-based profiles based on the PCT012 data for ZIP Code area 77077 (Houston, TX) are shown below. The tables have been developed using the ProximityOne Modeler2 software (more below).

Table 1. Single Year of Age by Race/Origin; 2010; ZIP Code Area: 77070

Click graphic to view full scroll section.

Table 2. Age by Race/Origin; Age Groups; 2010; ZIP Code Area: 77070

Click graphic for larger view.

Modeler2 Software
The Modeler2 software has been developed by ProximityOne to create demographic-economic estimates and projections at the sub-county geographic levels including census tracts and ZIP code areas. Annual estimates and projections are developed for 2010 through 2020 by single year of age, and for age groups, by census tract and ZIP code area.

The Modeler2 software can also be used to develop Census 2010-based SYOA profiles such as those shown above. While the Census 2010 PCT012 tables provide the basic data needed to develop these profiles, there is a lot that lies between the data existing and the development/availability of consumable data. As shown in the description of the PCT012 tables, the data are organized in Census 2010 SF1 as a set of tables that need to be separately accessed … and then transformed to a usable format. The Modeler2 software provides two options to access and use the basic PCT012 data: via a locally stored all U.S. dataset or via the Census API (a feature integrated into the Modeler2 software).

Members of the ProximityOne User Group can download and use Modeler2 Level 1 and create SYOA profiles for any county in the U.S. See the User Group section for more information about installation and use.

About the Author
— Warren Glimpse is former senior Census Bureau statistician responsible for innovative data access and use operations. He is also the former associate director of the U.S. Office of Federal Statistical Policy and Standards for data access and use. He has more than 20 years of experience in the private sector developing data resources and tools for integration and analysis of geographic, demographic, economic and business data.

Voting Age Population Demographics

Election  campaign strategies and decision-making … in congressional district, state legislative district and wide-ranging other elections, the question arises “what are the characteristics of the voting age population for neighborhoods throughout the district?”  Unless the election is not really contested, an understanding of voting age population demographics is essential to successful campaign planning and decision-making.  The most effective and winning campaign messages require knowledge of voter demographics.  This section reviews availability and use of Citizen Voting Age Population (CVAP) demographics by census tract and congressional district.

See Related Web sections (updated November 2015):
  • Citizen Voting Age Population Demographics – tract & block group
  • Citizen Voting Age Population Demographics – county & state
  • CVAP & Voter Demographics – characteristics of those voting in 2014 elections
  • Voting District Geography & Demographics

Data to Meet Voting Rights Act Needs
The Voting Rights Act prohibits development of voting districts that discriminate against potential voters on the basis of race and/or language/minority status. To examine how voting districts comply with the Voting Rights Act requires data on the Citizen Voting Age Population (CVAP) by race/origin for small geographic areas. The ACS 2011 5-year CVAP special tabulation provides these estimates for census tracts and block groups.

Scope of Subject Matter & Interactive Data Access
The scope of the CVAP subject matter is focused on total number of United States citizens for the geographic area total number of United States citizens 18 years of age or older for the geographic area, each cross-classified by several race/ethnicity groups. The estimates for the number of citizens and voting age population for each of the race/ethnicity groups is provided by census tract in this interactive table (click link to view). A list of the items/columns is presented below the table on that page.

Relating Census Tracts to Congressional Districts and Other Areas
The interactive table shows a row for each census tract in the U.S.  The second and third columns show the corresponding 113th Congressional District.  The graphic shown below illustrates how to associate census tracts with California 113th Congressional District 39.  California is selected.  The table now shows only California census tracts.  Click the CD column header and navigate to CD 39.  The first row in the table below, in CA-39, shows a Census 2010 population of 7,955.  The ACS 2011 5 year estimates include: total population 7,763, total citizens 5,220 and total voting age citizens 2,855.  Similar attributes by race/ethnicity can be viewed in columns further to right (requires scroll).

cvaptable39

Visual Analysis of CVAP Demographic Patterns
Using GIS tools, the CVAP demographics can be used in mapping applications to reveal potential Voting Rights Act non-compliance in the structuring of voting districts.  GIS tools can similarly be used to examine patterns of CVAP demographics of census tracts/neighborhood areas across congressional districts, state legislative districts — or any other political/statistical geography.

Percent Asian CVAP by Census Tract — Los Angeles County Area
The graphic presented below shows patterns of percent Asian CVAP population by census tract in the Los Angeles area.  Asian is used to illustrate, other race/origin groups could be used.
cvap_asian_la
Click the graphic or this link for a larger view and related details.

113th Congressional Districts are shown with brown boundaries and CD number as yellow label.  Green patterns show different percentage intervals of percent Asian citizen voting age population by census tract (see highlighted legend in panel at left of map).  The identify tool (see pointer) used to display mini-profile of data for a selected census tract. Profile for tract 06-037-408703 located in 113th Congressional District 39 shows the estimate of Asian citizen voting age population (3,235) in this tract in context of other citizen and voting age data.

Zoom-in for More Detail — Adding Voting Districts
The next graphic shows a zoom-in to the tract area profiled in the above view. This view has the added layers of Voting Districts 2010 (red bold boundaries) and roads/streets.  Using this view it is possible to examine the relationships between the voting districts and census tracts (green pattern; black boundary).
cvap_asian_la2Click the graphic or this link for a larger view and related details.

Next Steps
In summary, characteristics of the voting age population are not available from Census 2010, but they are available at the census tract and block group levels from the CVAP ACS 2007-2011 special tabulation.  What about updates?  2012 CVAP estimates can be developed for Public Use Microdata Areas (PUMAs) by using the 2012 ACS Public Use Microdata Sample (PUMS).  PUMAs are generally groups of contiguous census tracts and must be 100,000 or more total population.  Since congressional districts are around 650,000 population, CVAP estimates could be developed that typically subdivide congressional districts by six or more PUMAs.  Los Angeles County, for example, contains 69 PUMAs.  2012 CVAP estimates could be developed for each of these PUMAs.

About the Author
— Warren Glimpse is former senior Census Bureau statistician responsible for innovative data access and use operations. He is also the former associate director of the U.S. Office of Federal Statistical Policy and Standards for data access and use. He has more than 20 years of experience in the private sector developing data resources and tools for integration and analysis of geographic, demographic, economic and business data. Contact Warren. Join Warren on LinkedIn.