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Barack Obama has raised a ton of money and draws a hefty crowd everywhere he goes, but he's stuck in second place in the polls. One reason, according to his campaign, is that polls don't capture his young, cell phone-only fans. Researchers are concerned about more and more people ditching their landlines, but they also stand by their polls.
NPR's Audie Cornish reports.
AUDIE CORNISH: It's not that the number of people who have dropped their landlines in favor of their cell phones is all that large. It's that that number is growing like crazy.
Mr. SCOTT KEETER (Director of Survey Research, Pew Research Center): We were all scared to death in 2004 because you had a close race and the cell-only problem was already with us then.
CORNISH: That's Scott Keeter, the head of surveys at the Pew Research Center. Exit polls for the 2004 presidential election found some 7 percent of voters said they used their cell phones exclusively. Keeter says that number is likely to grow to nearly 15 percent by the 2008 election.
Pollsters have learned quite a bit about the cell phone-only users they do call. They are most likely to be under 30, unmarried, renters, making less than $30,000 a year and are slightly more likely to be black or Hispanic, says Keeter.
Mr. KEETER: The fact that they're very different is the potential problem for polling because it suggests that if there are enough of them and you're missing them in your landline surveys, then your polls are going to have a bias because of that.
CORNISH: Democratic pollster Anna Greenberg says surveying people on their mobile phones is labor-intensive and expensive.
Ms. ANNA GREENBERG (Senior Vice President, Greenberg Quinlan Rosner Research): If you're calling someone at home between five and nine, presumably the only reason they can't take a survey is they don't want to or they're washing the dishes.
But if you're calling someone with a cell phone, they might be driving, they might be in a meeting, they might be on a date. It meets all kinds of reasons why they would refuse to take the survey. So you just get higher refusal rates with the cell phones. You've got to call more people.
CORNISH: Since most people have to pay for the incoming calls on their cell phones, pollsters who do call them often try to offer a financial incentive to make it up to them.
Another problem for pollsters is that federal law bans the use of automated dialing services on cell users, so each call has to be dialed by hand. As a result, pollsters tend to avoid mobile numbers altogether.
But can we trust polls that don't capture this rapidly growing segment of voters?
Professor CLIFF ZUKIN (Public Policy, Rutgers University): Yeah. The early evidence is that we don't have a problem yet.
CORNISH: Cliff Zukin is a professor of public policy at Rutgers University. He points out that cell phone-only users are still a small group and are less likely to actually vote, especially in primary elections. Zukin says polltakers adjust the numbers for mobile phone voters the same way they do for any other hard-to-reach group. They take the answers of people with similar demographics and make their answers count for more, to reflect the group as a whole.
Prof. ZUKIN: The national surveys that I've seen suggest that telephone landline young people and the cell phone-only young people are very, very close. There's not a misrepresentation going on.
CORNISH: Still, says Anna Greenberg, that method won't hold for long, as people who use only mobile phones, Internet phones and the like, become the norm.
Ms. GREENBERG: In the long run, both pollsters and campaigns are going to have to figure out how to reach younger people, because as they age and become a bigger and bigger part of the electorate, their technological and communication habits are different than older voters. And we're going to have to completely rethink our technologies for communicating with them.
CORNISH: Greenberg says she's already experimenting with surveys that include a mix of landline, cell phone text message and Internet answers.
Audie Cornish, NPR News.