The growing number of households without a landline telephone is a major problem in survey research and the problem is especially troublesome in surveying young people, 33.5% of whom are cell-only. Overall, an estimated 20% of households are wireless, and that percentage been growing at the rate of about 2 points every six months. In fact, the landline non-coverage rate is as high today as it was in 1963, when the problem was households with no phones. As a result, young respondents are significantly underrepresented in landline-only samples; while official census data show the age 18-to-29 group at 22% of the total population,this age group makes up only 9% of the population in landline-only Pew Research surveys.To date, studies have shown that most of our survey estimates are not significantly biased if they rely only on landlines, with the findings subsequently weighted to census-based demographic distributions (the presidential horserace showed little difference when cell phones were included).However, the Pew Research Center and other organizations have recently begun including cell phones samples insurveys. Read More