Obama's Hidden Advantage :: "Cell-Phone Only" Voters

[jefferson_dem]

Pew Research: Missing Cell-Phone Onlys Matter

By Mark Blumenthal

Few in the field of survey research have examined the problem of cell phones and surveys as closely over the last four years as Scott Keeter and his colleagues at the Pew Research Center. They conducted one of the first large-scale political surveys by cell phone two years ago and have been leaders in testing and developing new methods to conduct political surveys by combining samples of landline telephones and cell phone.

Today they released a new must-read report summarizing findings from "three major election surveys with both cell phone and landline samples since the conclusion of the primaries." The verdict? "Pew's surveys this year suggest at least the possibility of a small bias in landline surveys."

The key details (emphasis added):

In each of the surveys, there were only small, and not statistically significant, differences between presidential horserace estimates based on the combined interviews and estimates based on the landline surveys only. Yet a virtually identical pattern is seen across all three surveys: In each case, including cell phone interviews resulted in slightly more support for Obama and slightly less for McCain, a consistent difference of two-to-three points in the margin.



Pollsters have long understood that the cell phone only population -- those who have cell phone but no landline telephone service -- tend to be younger, and that the growth of that population has made it more difficult to reach 18-29-year olds. However, the conventional wisdom among pollsters has held that weighting by age could mostly alleviate any potential bias, as they did they did in 2004.

The new Pew report shows why weighting by age may not have the same effect now:

Traditional landline surveys are typically weighted to compensate for age and other demographic differences, but the process depends on the assumption that the people reached over landlines are similar politically to their cell-only counterparts. These surveys suggest that this assumption is increasingly questionable, particularly among younger people. <...>

In the pooled data, cell-only young people are considerably less likely than young people reached by landline to identify with or lean to the Republican Party, and even less likely to say they support John McCain. Among landline respondents under age 30, there is an 18-point gap in party identification - 54% identify or lean Democratic while 36% are Republican. Among the cell-only respondents under age 30, there is a 34-point gap - 62% are Democrats, 28% Republican. The difference among registered voters on the horserace is similar: 39% of registered voters under 30 reached by landline favor McCain, compared with just 27% of cell-only respondents. Obama is backed by 52% of landline respondents under 30, compared with 62% of the cell-only.

The roughly two-to-three point difference in the margin favoring Obama is, as it happens, very close to the effect Nate Silver obtained over the weekend by comparing results from pollsters that have been interviewing by cell phone (including Pew) with a control group that has not.

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http://www.pollster.com/blogs/pew_research_missing_cellphone.php

[LynneSin]

1. That is so true - polling companies couldn't even poll me if they wanted to

I only use my cell phone.

[DemocratSinceBirth]

2. Some Pollster Contact Cell Phone Users

It's in the article...

[LynneSin]

4. Yes some - and that should be noted in the the polls we read

whether or not companies are using land lines or cell phones or a combination of both.

[Indiana_Dem]

3. That hopefully coupled with new voter registrations. nt

[LynneSin]

5. and those people who aren't qualified as 'likely voters'

There are people who only vote when a candidate inspires them to do so and I'm really seeing that with Barack Obama especially in the cities like here in Wilmington and also up in Philadelphia.

[NC_Nurse]

6. My family is one. My husband and I are way past that demographic...

my kids are all in though. We are all voting Dem. That's 5 votes for Obama right there and
NONE of us have a land line, none of us have been polled.

[DevonRex]

7. We don't have a land line and neither do our kids. So that's

four of us, plus my older son's girlfriend, who only have cell phones. Five people, 3 separate households, with no land line, and we've never been polled.

[DevonRex]

8. My in-laws also don't have a land line. They're elderly and

can't afford both a cell phone and a phone for the house.

So that's one demographic that is increasingly using just cell phones. And that may be a demographic that *might* trend McCain for various reasons.

BUT it seems that older voters are becoming wise to McCain, too. They don't like what he says about Social Security and they don't like certain things about his character. My in-laws had considered voting for him (mostly because of racism) but then decided against it when they found out more about him.

[yourout]

9. 4 Obama votes here...never been polled.