A few weeks ago, I highlighted some preliminary findings from a paper written by myself and Stephen Ansolabehere for this week's AAPOR conference. The paper is now finished and you can check out a copy. The data we use for the paper is the 2006 and 2008 Cooperative Congressional Election Study.
One of the major themes in the paper is that understanding the cell-only population is about more than just age. In fact, residential mobility has a strong influence on whether someone has shed their landline. Even after controlling for age and a litany of other demographic variables, we find that respondents who moved within the last year were 24 percentage points more likely to be cell only than those who had lived in the same residence for at least five years. Renters, singles, and those without children were also much more likely to be cell-only.
Our explanation for this pattern:
"There are several reasons that highly mobile Americans may be more likely to go without landlines. First, whenever someone moves from one residence to another, they have an opportunity to reassess their phone needs. Thus, the act of moving provides an opportunity for individuals to shed their landlines. Second, mobile Americans may choose a CPO lifestyle because cell phone numbers tend to be more portable than landlines. When moving from one metropolitan area to another, individuals must change their landline phone number, but do not need to change their cell number. This may provide an incentive for choosing not to maintain a landline in a new residence. Third, those with fewer family and community ties may feel less of a need to have multiple phone lines on which they can be reached by members of their social networks. "
The fact that the cell-only public tends to be more mobile has some important political consequences. Some highlights:
Ultimately, we argue that weighting for standard demographic measures such as age, education, income, and race may not be sufficient. Pollsters relying on landline samples may want to consider weighting by other factors such as time in residency, renter/home owner, and marital status. But check out thefor a more detailed discussion of all of these points.