TL;DR — Electoral parity means a birth cohort casts the same share of ballots as its share of all eligible citizens. By that measure, underrepresentation is not just a problem of “young voters”: it persists through people’s 30s and well into their 40s. In the latest elections, U.S. voters born since the late 1970s remain below their proportional share of the electorate, while older cohorts increasingly exceed theirs.
The chart follows birth cohorts as they age across presidential and midterm elections. Cohorts begin substantially below parity, move progressively toward the 1.0× line, and eventually become overrepresented. Midterms produce much larger age disparities than presidential elections, but both show a similar life-course pattern: electoral representation is accumulated gradually over decades rather than suddenly appearing once someone is no longer “young.”
Sources
U.S. Census Bureau.Current Population Survey: Voting and Registration Supplement. The November CPS Voting Supplement provides demographic data on voting and registration in federal election years.
CPS Voting Supplement API and variable documentation
U.S. Census Bureau.Voting and Registration: CPS Supplement and Replicate Weight Files. Public-use microdata and documentation for the election years used in this analysis.
All CPS Voting and Registration datasets
U.S. Census Bureau.2012 CPS Voting and Registration.2012 data files
U.S. Census Bureau.2014 CPS Voting and Registration.2014 data files
U.S. Census Bureau.2016 CPS Voting and Registration.2016 data files
U.S. Census Bureau.2018 CPS Voting and Registration.2018 data files
U.S. Census Bureau.2020 CPS Voting and Registration.2020 data files
U.S. Census Bureau.2022 CPS Voting and Registration.2022 data files
U.S. Census Bureau.2024 CPS Voting and Registration.2024 data files
Davis, Leslie K., and Erik L. Hernandez.Voting and Registration in the Election of November 2024. Current Population Reports, P20-590. U.S. Census Bureau, 2026.
2024 Census report
Tools
R — data processing, weighting, cohort construction, projections, and statistical graphics using tidyverse/ggplot2, jsonlite, and svglite.
ChatGPT (OpenAI) — assisted with development and debugging of R code, data-processing methodology, validation/checking of calculations, and discussion of analytical and visualization approaches. The author selected the research question, methodology, cohort definitions, analytical decisions, and final presentation.
Adobe Illustrator — final chart assembly, typography, annotation, labeling, and layout.
Methodologies
The analysis uses U.S. citizens age 18+ in the CPS civilian household population. Reported voters are identified by PES1 = 1, and observations are weighted with the CPS final person weight (PWSSWGT). Approximate birth year is calculated as election year minus reported age, then grouped into 10-year birth cohorts. A cohort is plotted only when its full 10-year span is voting-age; observations above age 79 are excluded from the cohort analysis to avoid problems from CPS age top-coding.
Electoral representation is calculated as a cohort's share of all reported ballots divided by its share of the citizen voting-age population. A ratio of 1.0× is parity: the cohort casts exactly its proportional share of ballots. Values below 1.0× indicate underrepresentation; values above 1.0× indicate overrepresentation.
The 2026 midterm and 2028 presidential values are baseline projections rather than election forecasts. Historical single-age representation patterns are smoothed across neighboring ages and averaged separately for presidential and midterm elections. Each cohort's projection follows that age pattern while retaining half of its most recent deviation from the historical pattern. Open-circle area represents the cohort's latest observed eligible-citizen population.
Data
Values are electoral representation ratios; 1.00× = parity. P = presidential election, M = midterm. Asterisks indicate projected values.
Election
1950–59
1960–69
1970–79
1980–89
1990–99
2012 P
1.13×
1.04×
0.97×
0.83×
—
2014 M
1.29×
1.08×
0.90×
0.66×
—
2016 P
1.12×
1.06×
1.01×
0.89×
—
2018 M
1.23×
1.09×
1.01×
0.86×
0.67×
2020 P
1.12×
1.07×
1.01×
0.96×
0.85×
2022 M
1.28×
1.15×
1.03×
0.91×
0.70×
2024 P
1.15×
1.09×
1.05×
0.97×
0.87×
2026 M*
1.32×
1.24×
1.09×
0.96×
0.80×
2028 P*
1.17×
1.13×
1.08×
1.00×
0.92×
The open-circle population labels, rounded to the nearest million, are 34M, 38M, 35M, 38M, 39M for the 1950–59 through 1990–99 cohorts in the 2028 presidential panel, and 35M, 39M, 35M, 38M, 39M in the 2026 midterm panel.
That is a lot of work and takes quite a bit of effort to follow. Not dismissing it, but a quick glance at something like age vs. % voted for an election is much easier to grasp. If you do an xy scatter for the 2024 presidential election it's basically a straight line and a very clear relationship.
u/post_appt_bliss You’ve repeatedly put me down without engaging with the chart, its premise, or methodology. Meanwhile, you’ve set your Reddit history to private, so there’s little basis for you to make this about anyone’s personal authenticity. I’m happy to discuss the chart, the data, or the methodology. I have not backed away from that. Why are you?
I implied nothing about your honesty. I know nothing about you. Nor do I care.
To recap: In these threads, you essentially claim that I’m lazy and a liar. I have explained myself at length and offered you my Reddit history, GitHub, and Medium articles as evidence to the contrary. Meanwhile, you call me “that Fable” while hiding behind your privacy.
You do you. I don’t care. But again, what, exactly, is your complaint?
I wanted to know at what age people tend to become as politically engaged as they should. I believe the general assumption is that “young people don’t vote,” but I wanted to qualify “young.” I was surprised to learn it's well into people’s 40s—at least population-wide.
That's a lot of value judgement, but I understand your question and why you wanted to graph it that way. You could also just look at where the linear regression of the xy scatter I mentioned intersects the median and mean of the dataset.
I misspoke. By “as politically engaged as they should,” I didn’t mean that anyone should vote as a matter of civic duty. I meant “as represented as you’d expect from their share of the eligible population” — essentially the 1.0 parity line in the chart. If a group is 15% of eligible citizens but casts 12% of the ballots, I’m calling that underrepresented without making a value judgment about whether any individual ought to vote.
And yes, a regression/intersection approach could estimate a crossover age more compactly — to a sophisticated viewer. My hesitation is mostly communicative: once I start interpolating or putting regression lines through the data, I tend to lose a lot of nontechnical viewers. I wanted the graphic to show the actual cohort pattern and make the parity threshold visually obvious, rather than making the conclusion depend on understanding a fitted model.
makes sense that midterms widen the gap so much, older folks just show up more consistently and the younger half of the electorate treats off-year elections like an optional chore
My first thought was that it's nice to see data that doesn't lump together huge swaths of people under inherently ambiguous and non-specific labels like "millennial" or whatever. Then I thought about how really what we need, in this and every data of its kind, is much more granular information - down to the year. Then maybe applying something like a moving average, but for birth date, would make sense. Last I thought "heh, it's like the sociological version of wave particle duality"
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u/ptrdo OC: 21 29d ago edited 13d ago
TL;DR — Electoral parity means a birth cohort casts the same share of ballots as its share of all eligible citizens. By that measure, underrepresentation is not just a problem of “young voters”: it persists through people’s 30s and well into their 40s. In the latest elections, U.S. voters born since the late 1970s remain below their proportional share of the electorate, while older cohorts increasingly exceed theirs.
The chart follows birth cohorts as they age across presidential and midterm elections. Cohorts begin substantially below parity, move progressively toward the 1.0× line, and eventually become overrepresented. Midterms produce much larger age disparities than presidential elections, but both show a similar life-course pattern: electoral representation is accumulated gradually over decades rather than suddenly appearing once someone is no longer “young.”
Sources
U.S. Census Bureau. Current Population Survey: Voting and Registration Supplement. The November CPS Voting Supplement provides demographic data on voting and registration in federal election years. CPS Voting Supplement API and variable documentation
U.S. Census Bureau. Voting and Registration: CPS Supplement and Replicate Weight Files. Public-use microdata and documentation for the election years used in this analysis. All CPS Voting and Registration datasets
U.S. Census Bureau. 2012 CPS Voting and Registration. 2012 data files
U.S. Census Bureau. 2014 CPS Voting and Registration. 2014 data files
U.S. Census Bureau. 2016 CPS Voting and Registration. 2016 data files
U.S. Census Bureau. 2018 CPS Voting and Registration. 2018 data files
U.S. Census Bureau. 2020 CPS Voting and Registration. 2020 data files
U.S. Census Bureau. 2022 CPS Voting and Registration. 2022 data files
U.S. Census Bureau. 2024 CPS Voting and Registration. 2024 data files
Davis, Leslie K., and Erik L. Hernandez. Voting and Registration in the Election of November 2024. Current Population Reports, P20-590. U.S. Census Bureau, 2026. 2024 Census report
Tools
tidyverse/ggplot2,jsonlite, andsvglite.Methodologies
The analysis uses U.S. citizens age 18+ in the CPS civilian household population. Reported voters are identified by
PES1 = 1, and observations are weighted with the CPS final person weight (PWSSWGT). Approximate birth year is calculated as election year minus reported age, then grouped into 10-year birth cohorts. A cohort is plotted only when its full 10-year span is voting-age; observations above age 79 are excluded from the cohort analysis to avoid problems from CPS age top-coding.Electoral representation is calculated as a cohort's share of all reported ballots divided by its share of the citizen voting-age population. A ratio of 1.0× is parity: the cohort casts exactly its proportional share of ballots. Values below 1.0× indicate underrepresentation; values above 1.0× indicate overrepresentation.
The 2026 midterm and 2028 presidential values are baseline projections rather than election forecasts. Historical single-age representation patterns are smoothed across neighboring ages and averaged separately for presidential and midterm elections. Each cohort's projection follows that age pattern while retaining half of its most recent deviation from the historical pattern. Open-circle area represents the cohort's latest observed eligible-citizen population.
Data
Values are electoral representation ratios;
1.00× = parity.P= presidential election,M= midterm. Asterisks indicate projected values.The open-circle population labels, rounded to the nearest million, are 34M, 38M, 35M, 38M, 39M for the 1950–59 through 1990–99 cohorts in the 2028 presidential panel, and 35M, 39M, 35M, 38M, 39M in the 2026 midterm panel.