10/26/2006 - Political pollsters continue to cast a wary eye on the growing number of Americans who only have a cell phone and no landline. The Pew Research Center estimates that this group now constitutes one-in-ten adults, and its demographic characteristics are very different from the landline population. But three Pew surveys of cell-only Americans this year, including a political poll earlier this month, have found that the absence of the "cell-only" population from telephone surveys is not creating a measurable bias in the overall findings. Pew's early October survey of 2,004 adults, conducted Sept. 21-Oct. 4 in conjunction with the Associated Press, included a sample of 200 people who were reached on their cell phone and said that they had no landline phone. As previous studies of the cell-only population have shown, this group is younger, less affluent, and includes a greater proportion of men and minorities than does the landline sample.

However, the political attitudes of cell-only respondents are not substantially different from the landline respondents. In the generic congressional ballot, the Democrats held a 20-point lead among the cell-only sample (54%-34%), and a more modest 13-point lead in the landline sample. But when the cell-only respondents are included with the respondents reached on a landline ­ and this blended sample is weighted to match the full U.S. population demographically and with respect to telephone status ­ the overall estimates of the vote are unaffected.

Read the full report Cell-Only Voters Not Very Different; Fewer Registered, More First-time Voters on the Pew Research Center Web site.