By knocking on voters' doors a month before election day – or even closer – organizers in Sacramento and other California cities significantly boosted turnout in areas where voters habitually don't show up at the polls, a new voter study says.

The study – by the nonpartisan California Voter Initiative – was funded by the James Irvine Foundation to increase civic involvement in the state. In California, studies show that 70 percent of those most likely to cast ballots in elections are white, even though whites make up just 47 percent of the adult population.

The study, released Tuesday, examined the results of nonpartisan get-out-the-vote drives over the last two years in north and south Sacramento, the town of Winters in Yolo County, sections of Los Angeles and areas in the Central Valley.

In Sacramento, two weekends before the February primary election, groups of youths, including a girls' basketball team, visited 2,807 addresses, and spoke with 732 registered voters. The youths reminded the adults to vote, and gave them cards with the addresses of where to go on election day.

After the election, researchers at Yale University and California State University of the East Bay compared who voted in canvassed areas against a control group that was not canvassed. Researchers found the voter drive increased turnout by nearly 15 percent.

"If someone expended that much energy to get you to vote, you'd feel bad if you didn't," said Jim Keddy, executive director of Sacramento Area Congregations Together, which is part of a network of religious congregations that helped organize the drives.

In Winters, Spanish-speaking residents with lists of voters with Spanish surnames knocked on 158 doors and talked to 143 voters. Their efforts boosted turnout by 13 percent.

Keddy said "political campaigns are about persuasion," and typically must begin long before election day to be effective.

But to get people to simply show up and vote, he said, it's more effective to talk to them closer to election day.

Renters, research shows, are among those least likely to vote because they don't receive updated information about where to vote if their precinct is moved. Voters can reregister as close as two weeks before an election.

Keddy noted that half of registered voters don't show up to vote in a typical election.

"If you could just get everyone who was registered to vote to go to the polls," he said, "think of what a difference it would make."

The Voter Initiative study also found that turnout increased if canvassers were local people, and that face-to-face contact was much more effective than mailers or fliers left on doorknobs.

Live telephone reminders to vote worked best, the study concluded, if organizers first cleared rolls of outdated numbers, called people with current numbers once, and then again if they seemed receptive.

As part of ongoing research, organizers plan another round of canvassing before the Nov. 4 election.

Canvassers are trained to remain nonpartisan. Keddy recalled observing high school and college students of various ethnicities – Hmong, Latinos, African Americans – as they "role played" to prepare to head out in February.

"It was one of the most inspiring moments of my entire career in community organizing," he said.

Call The Bee's Susan Ferriss, (916) 321-1267.