(iverson's) currentbuzz: Journalists, skeptics: Look out for polling data -- too many households are off the telecomm grid...

I have been discussing this with students for a couple of years:

"growing concern within the polling business about how long the landline telephone survey will remain a viable data collection tool, at least by itself." Source: centerformediaresearch.com

because with students, you see this trend up close. Lots of my colleagues who are 30 somethings are in this group too. Face it, if you moved, assuming you have been in the same place for five or more years, would you bother with a landline? This is a big worry for Public Opinion Researchers and pollsters and this will play havoc going into an election year in several ways I can imagine.

For political pollsters, note this finding "An analysis of young people ages 18-25 in one of the Pew polls found that the exclusion of the cell-only respondents resulted in significantly lower estimates of this age group's approval of alcohol consumption and marijuana use."

The bias this introduces into polls is obvious, though the exact impact of it on election results and such is debatable. Some fascinating things about the difference between polling via landline and cellphones include that one can't use auto-dialers on cellphones, it is more labor intensive (e.g. more expensive) to screen cell-only respondents-- as much as 5 times more expensive.

In early 2003, just 3.2% of households were cell-only. By the fall of 2004, pollsters and journalists were openly worrying about the potential bias that cell-only households might create for political surveys. The National Election Pool's exit poll found that 7.1% of those who voted on Election Day had only a cell phone, and these cell-only voters were somewhat more Democratic and liberal than those who said they had a landline telephone.
Source: centerformediaresearch.com

This is from Center for Media Research but you can read it from Pew, too.