For pollsters, a new wrinkle in the cell vs. landline puzzle

Another example of how changing telephone use is complicating polling: Pew Research and others have made persuasive arguments in recent years that pollsters who call only landlines and not cell phones tend to produce results skewed toward Republicans. But in a new report, Pew says the cell phone-landline effect is even more complicated than that.

Looking at what it calls dual users–voters who have both traditional hard-wired phones and cell phones–Pew found that which line they are polled on makes a difference. “Duals” reached on their cell phone “differ demographically and attitudinally from those reached on their landline phone. They are younger, more likely to be black or Hispanic, less likely to be college graduates, less conservative and more Democratic in their vote preference than dual users reached by landline.”

Mark Blumenthal, founder of, says the Pew findings add a new wrinkle to political surveys: “Future accuracy in polling may not be a matter of merely calling ‘cell phone only’ voters via cell phone. Pollsters may need to conduct parallel surveys of “dual users” via cell and landline phone.”