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University of Iowa News Release


Oct. 4, 2007

Rietz's research finds runoff elections hurt minority representation

Research by a University of Iowa business professor has found that minority-preferred political candidates are severely handicapped when they run in elections where the winner must get 50 percent of the vote to win without a runoff.

The research, by Tom Rietz (photo, left), professor of finance in the Tippie College of Business, looks at the electability of a candidates running to represent minority groups' interests against candidates preferred by majority groups. The research showed that, while minority-preferred candidates may get enough votes to win in multi-candidate races that don't require a majority of votes, they seldom achieve more than 50 percent. In the resulting runoff elections, they generally lose.

Rietz said the findings are important because 11 states require candidates receive 50 percent of the vote to win a statewide election. But since the rules in those states handicap minority candidates from the start, he said it's that much more difficult for minorities in those states to have a voice in government.

"We determined that runoff election systems can suppress minority representation in government," said Rietz, who conducted the research with Rebecca Morton, a former UI political science professor now teaching at New York University.

Election rules in other states, including Iowa, require the winning candidate to have only a plurality of the vote; that is, the most votes among the candidates whether it exceeds 50 percent or not. Reitz said the research shows a plurality system gives minorities a better chance to win.

Rietz said his research is not intended to directly measure the effects of racial and ethnic attitudes or composition on voter behavior, but is simply designed to measure the likelihood of a minority to win an election that requires a majority of votes.

The conclusions were drawn based on lab experiments that involved UI student volunteers voting in a series of 96 mock elections, 48 of them requiring a 50 percent vote total to win, the other 48 requiring only a plurality of votes to win. The students could vote for one of three candidates who represented designated views. One candidate was preferred by the minority of votes in each race while the majority of voters were split between the other two candidates.

The volunteers were paid, and in order to replicate the theory that voters cast their votes in self-interest, they were paid more when their designated candidate won.

In the 48 elections requiring a 50 percent vote to win, the minority candidate won only nine of them; six with an outright majority vote in the first round of voting, and three in runoffs. As the experiment proceeded, Rietz's research found that fewer and fewer minority voters were voting, suggesting that minority voters began to disenfranchise themselves as it became clear their candidate would have a difficult time winning.

Rietz said his experiment showed that plurality elections can increase minority representation. In the 48 plurality elections held in the experiment, the minority candidate won 38 of them, as the two majority candidates often split the majority vote.

"In our research, we're looking at the effects of different systems on minority representation in government, and under runoff elections, minority representation occurs far less often," Rietz said.

Rietz's and Morton's paper, "Majority Requirements and Minority Representation," will be published in a forthcoming issue of Annual Survey of American Law.

STORY SOURCE: University of Iowa News Service, 300 Plaza Centre One, Iowa City, Iowa 52242-2500

MEDIA CONTACTs: Tom Rietz, 319-335-0856, Department of Finance, Tippie College of Business,; Tom Snee, University News Services, 319-384-0010,