Over at Pollster.com, Mark Blumenthal calls our attention to a new study by the Pew Research Center on a subject that is often discussed among our commenters. Are polls getting thrown off by the fact that so many young people use cell phones only–and, therefore, don’t get polled? The answer: Possibly, though the effect is probably small. Blumenthal highlights this section, adding his own emphasis:
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.
UPDATE: Commenters Mattn and Kathy add a link to another recent post on the subject at fivethirtyeight.com, in which Nate Silver looks at the experiments that various pollsters are doing to figure out if there’s a “cellphone effect.”