The Cell Phone Challenge to Survey Research (PEW)

A few years ago I attended a meeting on the topic of Jewish research. In this room of Jewish lay people the lament was that phone interviews were no longer any good unless they utilized cell phone numbers (which were not available at the time). The concern was that any study done using land lines would not capture younger people who “all use only cell phones.” Not atypical for a group of professional Jews, this group felt certain that their opinions represented the truth and were more authentic than the opinion of the one professional researcher in the room.

I was concerned that we were missing something so I contacted a demographer later that week and asked whether there were any studies done on the topic of cell phone vs landlines for surveys. Not surprisingly the answer was yes, in fact one of the Granddaddies of all research institutions, PEW did a study in 2006. Their findings are significant to all of us so let me summarize.

Of the general public only 7 to 9% are cell phone only users.
The study says they are “significantly different in many ways from those reachable on a landline.” They are:
- younger
- less affluent
- less likely to be married
- less likely to own a home
- more liberal on many political questions

However, the study also found “the absence of this group from traditional telephone surveys has only a minimal impact on the results... changes the overall results of the poll by no more than one percentage point...”

Cell phone interviews present their own challenges. The study states that cell phone surveys are “more difficult and expensive to conduct than landline surveys” for the following reasons:

- most cell phone users pay for incoming calls so they must be offered an incentive for taking the call (in this study, $10). This incurs the cost of the incentive, ten dollars, and the cost of follow up mailings.
- federal law prohibits the use of automated dialing for cell phones thus each number must be manually dialed
- fewer cell phone users were willing to cooperate, that is, participate in the study (50% of landline users cooperated, 28% of cell users cooperated)
- more people reached on the cell phone were under the age of 18 and thus ineligible
- interviewer must first assert the cell user is in a safe place to take the interview

The study found that the total cost of interviewing the cell phone sample was 2.4 times the cost of the landline sample.


Cell Phone user demographics

Gender: More men were reached via cell phone (55%)
Age: Younger people were reached
Race: more minorities were reached (13% African American and 11% Hispanic)
Education: Interestingly, in this study both samples were better educated than the rest of the U.S. population
Home owners: Cell users were less likely to own their home
Children: Cell users were more likely to have children under the age of 18
Marital status: Almost the same rate for both samples, with landlines users 57% married and cell users 52% married

Two interesting and relevant issues for Jewish population studies:
The cell phone only population includes a higher proportion of minorities, especially Hispanics.
Landline samples includes a higher proportion of college graduates.

Jews are predominantly white and better educated, like the landline users.

These are all important factors to raise if you are involved in a survey or reviewing one.