If Obama Is Bouncing, Which Voters Are Moving?

The new science of winning campaigns
Sept. 10 2012 11:00 AM

If Obama Is Bouncing, Which Voters Are Moving?

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Obama is picked up by Scott Van Duzer during a visit toBig Apple Pizza and Pasta Italian Restaurant in Fort Pierce, Florida.

Photo by SAUL LOEB/AFP/GettyImages

So voters finally seem to be moving, part of what’s being called an Obama convention bounce. But who exactly is doing the moving?

I recently wrote about one of the “PocketTrial” lab experiments run by Adam Schaeffer of the Republican opinion-research firm Evolving Strategies.  Schaeffer randomly assigned an online sample of voters to watch either a Romney or an Obama campaign video, and then attributed change in each candidate’s support to the video’s influence.

The most interesting finding from the experiment was that male viewers were more easily susceptible to persuasion than female ones, shifting their opinion in response to both ads while women remained relatively stable. “A larger portion of men are decided, but the proportion that are conflicted are more variable,” Schaeffer says.

Schaeffer then looked at another dataset to see if it showed the same gender split.  He looked at the last eight samples from the Cooperative Campaign Analysis Project, for which the pollster YouGov surveys 1,000 respondents in weekly wave, stretching back from early July to just before the conventions. Each time, between 200 and 400 voters in the sample did not identify strongly with a party.

Schaeffer split that sub-sample by gender, and calculated the average share of undecided voters—in YouGov’s polls they’re categorized “not sure”—across the eight-week period.  He then looked at how much the number of undecided fluctuated week to week, by comparing the average to the wave in which it was highest and the wave it was lowest.  Among women, the mean “not sure” was 26 percent, an average between a minimum of 22 percent one week and 32 percent another.  Fewer of the men were undecided, but they swung more, from a minimum of 8 percent to a maximum of 22 percent around a mean of 15 percent. (In statistical terms, that means the number of standard deviations from the mean is 46 percent higher among men than women.)

The findings that the independent male vote is more volatile raises few possibilities.  Men could be moving more in this election, as Schaeffer’s lab experiment suggested: they’re more susceptible to persuasive messages for and against candidates.  But there could be a behavioral explanation, as well: what if men are more ready to commit to attach themselves to a new opinion after forming it—like, say, if inspired by by a welll-executed convention—and women are more tentative about making such a commitment?

Sasha Issenberg is the author of The Victory Lab about the new science of political campaigns.