Cellphone Only Households And Radio

There's a new survey of wireless/landline usage in the US by the National Center for Health Statistics and across all demographic groups the percentage of households that are cellphone only continues to increase. Overall 16% of households in the US are cellphone only. Even among 65+ households cellphone only has grown from .9% in 2004 to 2.2% at the end of 2007. The younger the respondent the greater the percentage of being cellphone only--18-24's are 34.5% cellphone only and 25-29's are 30.6% cellphone only. In the context of radio this trend continues to spell b-i-g trouble for ratings and Arbitron. At last December's Arbitron Radio Advisory Council Meeting the issue of cellphone only sampling was addressed: [note the updated stats in this post]

Mr. Cohen stated that the most recent cell-phone-only statistics from the government indicate that the cell-only percentage for the second half of 2006 was 11.8% overall and 25% among persons 18–24. He said that while the coverage of the landline telephone frame is deteriorating, the costs to recruit cell-only households using traditional telephone frame random-digit dialing (RDD) techniques is several orders of magnitude higher than the cost of recruiting landline households. Some reasons for the higher cost include the higher no-answer rate, lower cooperation rates and the fact that current laws and regulations prohibit the use of auto-dialers, i.e., cell-only household recruitment calls must be hand-dialed.

Arbitron is researching alternative means to bring cell-only households into the sample. The company currently is conducting a field test using an address frame to recruit households. Pending success of the tests, implementation could occur in some markets in 2009.

The Council expressed concern about Arbitron’s current practice of capping cell-phone-only households in its PPM New York service (and other radio first markets beyond Philadelphia) at 5%. Arbitron indicated that it was prepared to use the address-frame sampling method being tested in the Diary service to increase the cell-phone-only portion of the PPM sample if testing proves successful.

With all of the spirited debate recently regarding the ongoing PPM roll-out, largely over sampling, Arbitron is going to have to figure this out and quick. I don't know about you but I find the sentence, "Arbitron is researching alternative ways to bring cell-only households into the sample," frightening. Sounds like a process that is going to move at a snails-pace. Unfortunately, I have yet to hear or read anything that would cause me to adjust my thinking.

In essence, the "more real world accurate" PPM will deliver more accurate results from a potentially tainted and incomplete sample. It seems to me the very item that is causing this problem, cell phones, ought to be part of a future ratings solution.