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November 18, 2004

Fraud in Florida?

A quick note before anyone emails to ask whether I think these guys are "delusional" too. The release posted on RottenDenmark indicates that the team from the Research Center at the U. Cal. Berkeley will release evidence from some sort of new study. They "will report irregularities associated with electronic voting machines may have awarded 130,000-260,000 or more excess votes to President George W. Bush in Florida in the 2004 presidential election." Details will follow at a press conference later today, though I'm guessing their study is more than a rehash of the exit poll discrepancy. This is obviously a serious effort by a serious institution; it should be interesting.

To those who saw his post this morning, I believe Mr. Kaus slightly misread MayflowerHill in reporting that Warren Mitofsky "disprove[d] the idea that the no-paper-trail electronic voting machines in Florida were rigged" [emphasis added]. MayflowerHill's account makes no specific reference to Florida.

I am guessing that Mitofsky's analysis was done at the national level. When I described this method of analysis in earlier posts (here and here), I should have pointed out a few important limitations. Dr. Fritz Scheuren, VP for Statistics at the National Opinion Research Center (NORC) summarized the most important in an email on the AAPOR listserv a few days ago (quoted with permission):

Three cautions here. First the number of precincts under each method can get very small. Take Ohio for example where 75% of the voting was still done with punch cards and only 25% was electronic.

Second, the comparisons of voting outcomes are obviously not free of preexisting precinct differences, Such differences surely confound the results in a way that would be hard to adjust for, adding still more uncertainty.

Third, for some analyses it is the precinct, and not the voter, that is the unit of analysis and here the small number of precincts just about sinks us in any individual within state work that rely on exit polls.

The exit polls typically sampled 40-50 precincts per state (although Florida may have had more - it certainly had more interviews than other states). To analyze the source of the discrepancy with actual votes, Mitofsky's best unit of analysis would have been precincts not voters, so his ability to detect differences within a single state are limited.

Corrected mispelling of Berkeley 11/19.

Related Entries - Exit Polls

Posted by Mark Blumenthal on November 18, 2004 at 10:14 AM in Exit Polls | Permalink


Link with paper and data for Florida election study.


Posted by: Study Link | Nov 18, 2004 2:22:33 PM

Well, this study involves some esoteric multiple regression analysis, but here's the bottm line (its quite a mouthfull)


Electronic voting raised President Bush's advantage from the tiny edge he held in 2000 to a clearer margin of victory in 2004. The impact of the e-voting was not uniform, however. Its impact was proportional to the Democratic support in the county, i.e, it was especially large in Broward, Palm Beach, and Miami-Dade. The evidence for this is the statistical significance of terms in our model that guage the average impact of e-voting across Flor0da's 67 counties and statistical interaction effects that guage its larger-than-average effect in counties where Vice President Gore did the best in 2000 and slightly negative efffect in the counties where Mr. Bush did the best in 2000. The state-wide impact of these disparities due to electronic voting amount to 130,000 votes if we assume a "ghost vote" mechanism and twice that - 260,000 votes - if we assume that a vote mistattributed to one candidate should have been acounted for the other."

Posted by: Observer | Nov 18, 2004 3:11:49 PM

The study does not mention exit polls. They are using multi-variate linear regressions to explain voting patterns in Florida, and are finding a very statistically significant correlation between the presence of electronic voting and a higher percentage for Bush.

The paper has undergone some peer review prior to publication. It mentions two concerns that were raised about the methodology, and shows that when those concerns were addressed the findings did not change substantially.

So, what could cause the increase in votes for Bush in areas with e-voting? It's possible they have bad input data (their population estimates may be off, for example, although they are using US Census bureau numbers). Or possible that another variable they haven't identified could explain the difference.

Or it's possible that e-voting does skew votes (i.e. commit fraud). Since the e-voting isn't auditable, we can't know.

Posted by: Observer | Nov 18, 2004 3:14:13 PM

Hey, I was using "observer" first!

Posted by: observer (the first one) | Nov 18, 2004 3:19:02 PM

I'm Observer and so is my wife.

Posted by: Observer | Nov 18, 2004 7:47:37 PM

Opps, I guess I'll lobby for "Observer2"...:-)

Posted by: Observer2 | Nov 18, 2004 8:56:38 PM

Does this analysis hold up if you look at results from these counties in years prior to 1996. In looking a the results for Broward county from 1980 - 1992 the Repulican candidate won except 1992 and Perot got 90,000 votes that year.

Posted by: no one | Nov 19, 2004 10:41:36 AM

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