Estimating the U.S. Citizen Voting-Age 

Population (CVAP) Using Blended Survey Data, 

Administrative Record Data, and Modeling

J. David Brown

U.S. Census Bureau

October 25, 2023

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Any opinions and conclusions expressed herein are those of the author(s) and do not represent the views of the U.S. Census Bureau. All results have 

been reviewed to ensure that no confidential information is disclosed (CBDRB-FY23-272).
ACS Housing Unit Response Rate (Percent)

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Motivation 

• Traditionally, survey weights of the respondents are adjusted for nonresponse bias

• We use administrative data for nonresponding housing units

• We replace edited and imputed survey citizenship responses with administrative data 

and modeling

• Report documents differences in estimates across methods and analyzes why they are 

different

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Enhanced CVAP Methodology

• All people in final 2016-2020 ACS responses for 50 states and DC are used

• ACS values for age, race, and ethnicity are not altered

• As-reported ACS citizenship values are not altered

• ACS citizenship values that are not as-reported are replaced with values from administrative or past as-reported survey data when available, and are modeled otherwise

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Enhanced CVAP Methodology

• Place people from 22 administrative data sources in nonresponding ACS 

housing units

• For administrative records with month, use 25-month window around ACS 

tabulation month – otherwise a 3-year window

• Exclude persons not alive or who were incarcerated in Bureau of Prisons in 

ACS tabulation month 

• Age is from SSA NUMIDENT

• Race and ethnicity are from past decennial census, survey, and administrative 

data

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Enhanced CVAP Methodology

• Predict probability that person resided at ACS address in tabulation month

• Logistic regression model using 2016-2020 ACS responses

• Indicator for whether the person in administrative records at this address is 

also in this address’s ACS response is dependent variable

• Explanatory variables include indicators for administrative record sources, a 

duration in days from ACS tabulation month for each source, and the first and 

last year the PIK-MAFID appeared in any source

• Person-place probabilities are normalized by dividing the original probabilities by the sum of all their administrative record address probabilities in the 

window around the ACS tabulation month

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Enhanced CVAP Methodology

• Each person has a weight that is specific to their citizenship-age-race- ethnicity-location cell, via multiplying their probabilities of being in the citizenship category, age category, race-ethnicity category, and location

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Noncitizen Shares by Age and Race/Ethnicity for All ACS Housing Units and Group Quarters

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The data presented in this table are approved for dissemination by the DRB (CBDRB-FY23-272).

ACS Enhanced CVAP Percentage Point 

Difference Percent Difference

Total 6.64 7.38 0.74 10.56

Age 0-17 2.51 2.18 -0.33 -14.07

Non-Hispanic 1.84 1.88 0.04 2.15

Hispanic 4.49 3.08 -1.41 -37.25

Age 18+ 7.86 8.88 1.02 12.19

Non-Hispanic 4.19 4.80 0.61 13.57

Hispanic 26.93 29.98 3.05 10.72
Association Between Enhanced CVAP – ACS Percentage Point Difference in 

Noncitizen Share and Percent Hispanic in Voting Age Population

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The data presented in this figure are approved for dissemination by the DRB (CBDRB-FY23-272).
Percent of Voting-Age Population by Race/Ethnicity 

Responding ACS Housing Units

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2020 Census 2020 ACS 2020 AR

Non-Hispanic Asian 6.50 6.50 5.74

Non-Hispanic Black 8.49 8.11 8.72

Non-Hispanic White 69.10 69.08 69.81

Hispanic 12.68 12.89 13.41

The data presented in this table are approved for dissemination by the DRB (CBDRB-FY23-272).
Percentage Point Difference in Race/Ethnicity Share of Adults 

Nonresponding - Responding ACS Housing Units

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2020 Census 2020 AR 2020 ACS

Non-Hispanic Asian -0.51 -0.62 -1.11

Non-Hispanic Black 5.69 5.65 6.03

Non-Hispanic White -12.79 -12.61 -10.59

Hispanic 7.44 7.44 6.40

The data presented in this table are approved for dissemination by the DRB (CBDRB-FY23-272).
Decomposition of Difference in Percent Voting-Age Noncitizens between ACS and 

AR in Nonresponding 2016-2020 ACS Housing Units

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AR and Modeling in 

Place of ACS Edits 

and Imputes in 

Responding HUs

AR and Modeling in 

Place of AsReported ACS 

Citizenship

AR Rosters in Place 

of ACS Rosters

Difference in AR 

vs. ACS Change for 

Nonresponding vs. 

Responding HUs

Total Percentage 

Point Difference in 

Noncitizens

Non-Hispanic 0.08 -0.02 0.76 1.14 1.96

Hispanic 0.89 0.01 4.21 1.08 6.19

The data presented in this table are approved for dissemination by the DRB (CBDRB-FY23-272).
Conclusions

• Enhanced CVAP method produces 0.74 percentage point higher noncitizen 

share, and 3.05 percentage points higher for voting-age Hispanics

• AR data include more voting-age Hispanic noncitizens with unknown legal status than ACS responses do

• ACS nonresponse bias weight adjustments by citizenship are less than what 

AR data suggests is the case

• AR and 2020 Census indicate similar levels of nonresponse bias by age and 

race/ethnicity 

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The data presented here are approved for dissemination by the DRB (CBDRB-FY23-272).
Questions?

The report is available at: https://www.census.gov/library/working-papers/2023/adrm/CES-WP-23-21.html

Contact information: j.david.brown@census.gov 

Disclosure Prohibited - Title 13 U.S.C and Title 26 U.S.C 14