E-Voting News and Analysis, from the Experts

Friday November 19, 2004

New Study of E-Voting Effects in Florida

Filed under: — Felten @ 10:09 am PST

Yesterday, a team of social scientists from UC Berkeley released a study of the effect of e-voting on county-by-county vote totals in Florida and Ohio in the recent election. It’s the first study to use proper social-science modeling methods to evaluate the effect of e-voting.

The study found counties with e-voting tended to tilt toward Bush, even after controlling for differences between counties including past voting history, income, percentage of Hispanic voters, voter turnout, and county size. The researchers estimate that e-voting caused a swing in favor of Bush of up to 260,000 votes in Florida. (A change of that many votes would not be enough to change the election’s result; Bush won Florida by about 350,000 votes.)

No e-voting effect was found in Ohio.

The study looks plausible, but I don’t have the expertise to do a really careful critique. Readers who do are invited to critique the study in the comments section.

Regardless of whether it is ultimately found credible, this study is an important step forward in the discourse about this topic. Previous analyses had shown differences, but had not controlled for the past political preferences of individual counties. Skeptics had claimed that “Dixiecrat” counties, in which many voters were registered as Democrats but habitually voted Republican, could explain the discrepancies. This study shows, at least, that the simple Dixiecrat theory is not enough to refute the claim that e-voting changed the results.

Assuming that the study’s authors did their arithmetic right, there are two possibilities. It could be that some other factor, beyond the ones that the study controlled for, can explain the discrepancies. If this is the case, we can assume somebody will show up with another study demonstrating that.

Or it could be that e-voting really did affect the result. If so, there are several ways this could have happened. One possibility is that the machines were maliciously programmed or otherwise compromised; I think this is unlikely but unfortunately the machines are designed in a way that makes this very hard to check. Or perhaps the machines made errors that tended to flip some votes from one candidate to the other. Even random errors of this sort would tend to affect the overall results, if e-voting counties different demographically from other counties (which is apparently the case in Florida). Another possibility is that e-voting affects voter behavior somehow, perhaps affecting different groups of voters differently. Maybe e-voting scares away some voters, or makes people wait longer to vote. Maybe the different user interface on e-voting systems makes straight party-line voting more likely or less likely.

This looks like the beginning of a long debate.

8 Comments »

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  1. here’s a bit more:

    http://electionlawblog.org/archives/002465.html
    http://equalvote.blogspot.com/2004_11_01_equalvote_archive.html#110082792669339796
    http://www.mysterypollster.com/main/2004/11/the_ucal_berkle.html

    Comment by joe — Friday November 19, 2004 @ 2:42 pm PST

  2. Interestingly, this study shows the opposite effect from what many had concluded from previous, informal research: counties with paperless voting supported Bush more heavily than counties with optical scanning did. But it is consistent with the possibility that the paperless voting machines were rigged.

    Of course, it’s also consistent with the possibility of a design flaw similar to the one with our eSlate machines here in Texas, where straight-party Democratic voters could easily vote for Bush by accident.

    One way to distinguish between these possibilities would be to do a similar study of Florida’s Senate race, which was also close. If the same pattern emerges, it would suggest rigging (and in that case, might 260K votes have swung the Senate race?); if not, it would suggest a design flaw. Is anyone familiar with the Florida machines who would care to comment on this?

    Comment by Mathwiz — Friday November 19, 2004 @ 6:12 pm PST

  3. You believe it is “unlikely” that the machines could have been maliciously programed? You are kidding, aren’t you? The head honcho at Diebold is on record as saying he would do “anything” he could to deliver the election to Bush. Could that possibly, just maybe, include rigging his machines?

    This is like saying, “everybody is basically good, down deep.", a notion disproved repeatedly throughout history. Of course they rigged the machines. If they could, they would. Because they know they don’t have the votes. csb

    Comment by Chris Brudy — Sunday November 21, 2004 @ 9:07 am PST

  4. This critique points out that the “e-voting” effect is actually caused by only two of the e-voting counties: Broward and Palm Beach. If some other factor explains the swing in those two counties, then e-voting was not in fact a significant effect.

    Comment by Matt Brubeck — Sunday November 21, 2004 @ 11:34 am PST

  5. You say: “The researchers estimate that e-voting caused a swing in favor of Bush of up to 260,000 votes in Florida. (A change of that many votes would not be enough to change the election’s result; Bush won Florida by about 350,000 votes.)” Hey, I’m just a lawyer, and math is not my forte. But isn’t it true that if you take, say, 200,000 miscast votes away from Bush’s total, that reduces his lead to 150,000? And that if you add those same 200,000 votes to Kerry’s total, Kerry wins by 50,000? Am I missing something?

    Comment by Martha Bablitch — Monday November 22, 2004 @ 10:43 am PST

  6. This critique points out that the “e-voting” effect is actually caused by only two of the e-voting counties: Broward and Palm Beach. If some other factor explains the swing in those two counties, then e-voting was not in fact a significant effect.

    So much for my design flaw hypothesis. One wouldn’t expect the effects of a design flaw to be limited to two counties.

    If the machines were rigged, at least now we know where to look. But it’d probably have been just as easy for the Florida GOP to influence the vote in Broward and Palm Beach counties through tried-and-true means (voter suppression, long lines due to too few machines in Democratic precincts, etc.) than through rigging the machines.

    Comment by Mathwiz — Monday November 22, 2004 @ 2:27 pm PST

  7. The paper starts by saying statistical analysis is the only method for proving the validity of eVoting. I understood that comparisons can also be made with exit polls. This has not be done. Can we also derive a relationship between eVoting and the make of eVoting machine? Any faulty machine type could be tested and have its software source code analysed (and compared against reversed engineered code to see whether the code is an accurate reflection of the source code). IMHO, you need a paper audit trail - surely paper-and-a-scanner solution is cheaper than touch screen computer screens, anyway!?

    Comment by Andy Pritchard — Monday November 29, 2004 @ 3:02 pm PST

  8. If I understood the paper correctly, it looked at behaviors
    of observed changed votes between 1996, 2000, and 2004.

    That would give a rough upper bound on evote error, but a horrible
    lower bound, since things do change, or we wouldn’t have to hold
    elections to figure out who won.

    That is to say, this is about putting bounds on the worst
    case, and shouldn’t be taken as saying anything about likely
    magnitude of phantom evote.

    Comment by Jon Kay — Wednesday December 01, 2004 @ 5:20 pm PST

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