Voting irregularities in three Florida counties that used electronic voting machines may have awarded as many as 130,000 votes to president George Bush in the US presidential election, according to researchers at the University of California, Berkeley.
The researchers claimed that their findings raise questions about the accuracy of voting results in Broward, Palm Beach and Miami-Dade counties, all of which have more voters registered as Democrats than Republicans.
According to statistical models, voters in those three counties delivered more than 130,000 votes to Bush than were expected by a post-election analysis, the researchers maintain.
"Something went awry with electronic voting in Florida," said Michael Hout, a sociology professor, who led the research effort.
Hout said that the odds of the Florida irregularities happening by chance were less than one in 1,000 and he called for an examination of the results.
"It is like a smoke alarm and it is beeping," he said. "We call upon the voting officials in Florida to determine whether there is a fire."
The irregularities did not account for enough votes to give the state to Democratic challenger John Kerry, who lost to Bush in Florida by more than 377,000 votes.
To obtain their results, the Berkeley researchers analysed publicly available voting data from all Florida's counties using a technique called multiple-regression analysis, which accurately identified butterfly ballot problems in Palm Beach County during the 2000 election, Hout said.
The technique involves building a statistical model to predict voting patterns based on a number of factors, including history of voting, median family income, age and race. Hout's team conducted their study using data compiled from the 2 November election.
"We noticed that three counties stood out from those expectations," Hout said. "These were counties that had a significant departure from what we would expect, statistically, given the patterns in all those other counties."
Using their statistical model, Hout's team forecast that Bush should have received 28,000 fewer votes in Broward County than he received there in 2000. However, Bush received 51,000 more votes than he did four years ago.
In Palm Beach County, where Bush gained 41,000 votes, the research suggested a loss of 8,900 votes. For Miami-Dade County the research showed Bush should have gained 18,400 votes. In fact, he gained 37,000 votes.
The counties in question used e-voting machines manufactured by Election Systems & Software and Sequoia Voting Systems.
The model found an even larger discrepancy when certain factors weighing the data in Bush's favour were removed, Hout said.
However, the team did not find this level of irregularity in 12 other Florida counties that used e-voting machines, he said.
Hout was unable to explain why some e-voting counties would experience irregularities while others did not, but he said that the irregularities were more likely to occur in counties that voted for Democratic candidate Al Gore in 2000.
"This becomes an important clue that investigators who know something about both the software and the hardware can use," he said.
The Berkeley study also appeared to debunk speculation about voting irregularities in several heavily Democratic counties that voted Republican in the 2004 election.
After applying the statistical model to Dixie County and Baker County, both of which bucked party affiliations and voted overwhelmingly for Bush, Hout's team found nothing amiss. These counties, which used paper ballots that were optically scanned, have historically voted Republican in national elections, Hout said.
Hout's researchers also examined the election results in the hotly contested state of Ohio and found no irregularities there. "Our results do indicate that Ohio probably did get it right," Hout said.
A spokesman for the Information Technology Association of America (ITAA), an IT supplier group, dismissed the results, saying that the study appeared to ignore the political, social and economic factors that affected the vote.
"It is unclear to us that the technology, which is the one factor the authors appear to have focused on for this study, should be viewed as causal above the many other factors that could affect a voter's decision," said ITAA spokesman Charles Greenwald.
Greenwald also criticised the study for not being peer reviewed.
The Berkeley research has already been informally reviewed by academics at Harvard University, and will no doubt be scrutinised now that the results are posted on Berkeley's website, Hout said.
He declined to provide the names of researchers outside of Berkeley who were familiar with the results, saying they asked not to be identified. The results can be found at http://ucdata.berkeley.edu
Because there is no paper audit trail for the e-voting machines used in Florida, it may be difficult to ultimately explain the irregularities.
"Our statistical approach is just about the only way we have to uncover what went on in Florida or in any other state that uses e-voting as it exists today, except Nevada where there is a paper trail," Hout said.
Robert McMillan writes for IDG News Service