Behind the Numbers – Pew: cellphone bias may be bigger than in ’08

Interesting….

The Cell Phone issue is going to be much clearer after November…

In a new analysis sure to add to the uncertainty about the upcoming election, the Pew Research Center reports that a large number of pre-election polls might be biased.

Polls that don’t interview people on cellphones are producing potentially inaccurate results, according to the Pew study. The vast majority of political polls today only interview on conventional, landline telephones.

Looking at their most recently released poll, Pew shows that a 7-point Republican advantage on the generic congressional vote question would have been a wider 12-point lead had they not included cellphone interviews. Three of four other Pew polls this year would have shown similar tilts toward the GOP, leading to Pew’s conclusion that “the bias [from not using cellphones] is as large, and potentially even larger, than it was in 2008.”

Nationally, Pew and some others (including The Washington Post) interview on cellphones, but few state- and district-level polls do so. Almost no automated polls include cellphone samples, in part because of the legal prohibition against having computers dial cellphone numbers. Approximately 25 percent of all U.S. adults are “cell only.”

While Pew’s update to their long-running research on cellphones and surveys isn’t a broad rebuke to pollsters who don’t interview on cellphones, it raises fresh doubts about the precision of the reams of polling data fueling estimates of what may happen on Nov. 2.

via Behind the Numbers – Pew: cellphone bias may be bigger than in ’08.