Proponents of Oakland's Measure O say it will save taxpayers money, improve voter turnout and reduce negative campaigning.

If approved by a simple majority of Oakland voters on Nov. 7, the measure would institute instant runoff voting in Oakland, a method already used in San Francisco and approved for use in Berkeley.

Its detractors include City Councilmen Larry Reid and Henry Chang, who voted against switching to instant runoff voting when the City Council agreed in July to put the issue on the ballot, saying it is too confusing and could lead to fewer people voting.

"It's not that complicated," said Judy Cox, a member of the Yes on Measure O executive committee. "All voters have to do is pick their first, second and third choice, like we do in a lot of areas of our lives, whether it be work goals, football pools. Even little kids can rank their favorite toys."

Also called ranked-choice voting, the voting system allows voters to pick their top three choices for any race. If no one gets more than 50 percent of the vote, the candidate with the fewest first-place votes is dropped from the race. On the ballots where that candidate was listed as first choice, the second choice moves to the top spot and the ballots are recounted. The process continues until someone has a majority.

Instant runoff voting would end the city's use of primaries and consolidate elections in the fall, when typically more people vote. That would save more than $300,000 per year, Cox said.

If approved, Oakland's instant runoff would begin in the November 2008 election.

"We think it's very desirable," said Cox, a member of the League of Women Voters of Oakland, which has endorsed instant runoff voting, along with the Green Party and many Democratic elected officials. "If we have IRV, we don't have to have a second runoff election, so all local elections can move to November when almost 60 percent more people are voting."

Cox said research conducted by the pro-Measure O committee indicates minority participation is higher in November elections.

Councilmember Reid said he's seen no evidence to show ranked-choice voting increases voter participation.

"If you want to get people to participate in the political process, you have to get them registered to vote and empower them to be part of the process," he said. "Even groups that do this haven't been successful in increasing voter turnout. I think people will be confused by instant runoff voting. Proponents also say it gives people a choice. Every time I've run for office, people have had a choice. I've always had opponents."

Oakland's primary election in June featured a mayoral race, three City Council district races, a city auditor's race, and choices for county and statewide officeholders and ballot measures. All told, 86,379 voters cast ballots in June's election -- 46 percent of Oakland's registered voters.

Although voters elected a new mayor and re-elected two council incumbents, one council seat and the auditor's race remain undecided because no candidate in those two contests received more than 50 percent of the vote. Voters will pick between the top two candidates in each of those races on Nov. 7.