making voter pie

This post is co-authored by Daniel Laurison and Dan Hirschman.

There has been a compelling pie chart circulating on Facebook and Twitter, showing the percentage who voted for Trump or Clinton, or who didn’t vote, or weren’t eligible. (Dan even went so far as to include the image in this past week’s Sunday Morning Sociology link round-up, contributing to that circulation.) The problem is … well, there are a couple problems. First of all, the chart mostly circulated without an associated story or link, just some vague source info that couldn’t be traced back to any explanation of what the pie chart really meant. The closest to the original we could easily find was this, where the chart is reproduced (as below) with no contextual information.

2016electionpie

But the second, related, problem was bigger, and was driving both of us nuts: the mystery of the denominator. The image shows that only about 41% of Americans voted, but turnout estimates we’d seen said 55% – 60% of eligible voters voted. More surprisingly, it showed that nearly 29% of Americans weren’t eligible to vote. We know felon disenfranchisement is a problem (see Uggen et al’s work here), and of course that there are immigrants in the US who aren’t citizens. But those two populations aren’t anywhere near a third or even a quarter of the US.

totaluspoppie
Total US Population’s Eligibility and Participation in the 2016 Presidential Election. Sources here

We both guessed that that 28.6% must include kids, but usually we don’t think of children as “ineligible” to vote in the same way that disenfranchised felons are. So we didn’t think the chart was right – or at least we were sure it was confusing – and so we made our own. The file with sources and links to those sources is available here.

For our first chart, we attempted to replicate the WaPo chart, and the two are quite similar. Our denominator is the total US population estimated by the census on November 8th 2016, plus the 4.7 million US citizens eligible to vote but living outside the country; about 328 million people total. To the extent that we can tell, it looks like the numbers for Clinton & Trump votes in the WaPo image were from before all the votes were counted (approximately mid-November, we later learned). But the most important takeaway is that a big portion of those “ineligible to vote” in the first image are in fact children: about 22% of the total. Out of the Washington Post’s 28.6% ineligible, only about 6% are adults who were not eligible to vote.

usadultpoppie.png
US Adult Population’s Eligibility and Participation in the 2016 Presidential Election. Sources here.

Next, here’s the chart that many people thought that they were seeing, one whose denominator was the percentage of the US-Resident and/or Citizen Voting Age Population. 7.6% of US-resident adults are not eligible to vote. That’s about 19.5 million people; most of those are residents of the US who are not citizens (immigrants who have not naturalized); the rest, about 3.2 million people or 1.27% of voting age adults, are disenfranchised felons – people who are either currently in prison, or on probation or parole, or have served their time fully, in states where voting rights are taken away from them. (These estimates come from the United States Elections Project, run by political scientist Michael McDonald, one of the sources for the original WaPo chart.)

eligiblevoterpie.png
US Eligible Voters’ Participation in the 2016 Presidential Election. Sources here.

Finally, here’s the breakdown for just eligible voters. Nearly 42% of those eligible to vote did not. We can’t know from these sorts of numbers exactly who those people are or why they didn’t vote, but there is a lot of research on who votes and who doesn’t, so we can make an educated guess that the non-voters are on average younger, less educated, and less well-off than the voters for either party. We also know that new, restrictive voter id laws had some effect in turning away eligible voters, disproportionately affecting minority voters.

What lessons can we learn from this? First, in fractions, the denominator makes a big difference! Second, after a bit more digging, we found what seems to be the first instance where the chart appeared in the Washington Post, in this article, which explains the chart in more detail (including noting that children make up most of the ineligible category). But the chart had become de-linked from the metadata, so to speak. So another takeaway is that you have to be very careful when you create and circulate data visualizations. You can’t assume that the visualization will remain in its original context, especially when it has viral appeal and touches on a subject people think they understand. Third and finally, if you want to suck up a lot of geeky social scientist time, post some nearly-accurate but slightly misleading numbers with poor sourcing, and there goes our evening.

Author: Dan Hirschman

I am a sociologist interested in the use of numbers in organizations, markets, and policy. For more info, see here.

13 thoughts on “making voter pie”

  1. Daniel and Dan, thanks so much for this. I understand that the point of the pie chart is to show clearly that a minority of Americans actively voted for Trump, but do we have any reason to believe the eligible adults have preferences that are any different from voters? I mean, I understand that the non-eligible voters is heavily biased toward groups that would vote Democrat, and that this is by design. I also know that many of the “voter fraud” restrictions to suppress turnout among eligible voters were targeted toward African-Americans, who vote strongly Democrat. But in the larger group of disenchanted non-voters, is there some reason to believe that this group is biased by party, too? My assumption would be that they are similar to the voting group.

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    1. Hi! So, there are reasons to think that the preferences of non-voters are different from those of voters, though I think you are right to note that the differences are not as massive as some who circulate charts like this would like to believe.

      For a related, post-election example, an analysis by Pew showed that surveys of likely voters had Trump’s approval just above 50, registered voters in the mid-40s, and all adults in the low 40s. In other words, Trump seems to be systematically more popular among those likely to vote.. but not by *that* much. Adding in non-voters to approval polls drops Trump by a few points, but that means that a big chunk of those 45% of non-voters must approve. They summarize at the end:

      “While nonvoters do lean more Democratic than Republican, it would be a mistake to cast them as a partisan lot. Overall, they are much less likely than registered adults to identify with either major party (24% don’t lean toward either party, compared with 6% among voters). So polls that exclude nonvoters don’t just change the shade of the country’s partisan balance, they paint a portrait of a public that is distinctly more politically engaged and ideological than those that survey all adults.”

      Make of that what you will. Our point here was mostly about our annoyance at having to spend an evening to figure out that “ineligible” here mostly meant “kids”, and then posting in part because we were worried that folks were getting a very misleading impression of the size of e.g. felon disenfranchisement (a serious problem, but not a 26% of the population problem).

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      1. Thanks, Dan. That is very interesting. Plus, I get it that elections are a game in which splitting hairs have profound consequences, which is why all the voter suppression and denial of voting rights to felons and former felons matters greatly. But knowing that non-voters preferred Dem slightly is a pretty important part of the story that is good to know.

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  2. I’d like to use this chart in a talk (with attribution). 1) may I? and 2) is there any chance you might post higher-resolution images (especially of the US Adults chart)?

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    1. 1. Please do! But keep some kind of link back to either this post or the underlying data:
      https://docs.google.com/spreadsheets/d/1KcOyM3-rn96XaGmRHgoc1W9BcTRzvv91JzlmHXIdvYw/edit#gid=0

      2. If you follow that link you can see the original charts. For some reason, it’s difficult to get Google to produce a hi-res version of the images. Here’s an interactive version of the chart:
      https://docs.google.com/spreadsheets/d/1KcOyM3-rn96XaGmRHgoc1W9BcTRzvv91JzlmHXIdvYw/pubchart?oid=28187006&format=interactive
      Taking a screenshot of that might get you a slightly higher-res version. Apologies!

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  3. Thank you for solving this mystery. Terrific post. And thanks for sharing your data. I couldn’t help but do a little re-visualizing of the original WaPo graphic. They used red and blue to signify party – but red jumps out so it can screw with interpretation, especially when % difference is so small. I thought a bar chart with numbers, not percents, might make the point more vividly. If of interest, revizzes here: Facebook.com/DaveyStrategies

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