Are young people who use landlines more conservative than young people who use mobile phones?

Apparently so, according to the Pew Research Center for the People & the Press. The Pew project recently got interested the question of whether the explosive growth of mobile phones is making traditional polls irrelevant. Political polls generally only use landlines to collect their data, but young people — classified as those “under 30” — are more and more foregoing landlines in favor of using only a mobile phone. (As my last blog entry documented, only 1% of incoming students at Amherst college have a landline.) Since young people are also much more likely to be Democratic, the armchair critique is that traditional landline polls underreport Democratic support across the country, and overreport Republican support.

Is this really true, though? A group of Pew researchers decided to test the hypothesis. So they did three polls this year in which 20-25% of the people polled were reached by mobile phone — and then they compared them to polls done purely via landline. The conclusion? Sure, the mobile-phone people were much younger and more Democratic. But because traditional landline polls are weighted to compensate for age and other demographic differences, they were already pretty well capturing the youthquake. When the Pew people added in the mobile-phone interviewees, it didn’t change the poll results more than 2%, which is within the margin of errror. “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,” as the Pew researchers wrote in a report on their findings two days ago.

So, all’s good, right? For now, possibly. But along the way, the Pew people found something different, and really fascinating:

Young people who use landlines are more likely to be Republican than young people who use mobile phones.

They discovered this when they pooled all the under-30s who been polled via landline and compared them to the under-30s who’d been reached on their mobiles. As the Pew researchers report …

… 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 researchers didn’t offer any hypothesis as to why this would be so, but it’s kind of interesting to speculate, eh? Why precisely would mobile-only youngsters be more Democratic than their peers who use landlines? What sort of ideological, psychological or personality elements underpin a desire to avoid landlines, and stick to mobiles?

It’s worth figuring out, because in the long run it will begin to affect landline polls. Why? Because, as the Pew researchers note:

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.

Emphasis mine. Interesting stuff, either way!

(That photo above is courtesy arbyreed’s Creative Commons Flickr photostream!)