Arbitron plans to expand the introduction of cell-phone-only sampling to 151 diary markets in spring of 2009 and to all markets (except Puerto Rico) by next fall. This is seen as key to reaching young adults, especially males.
Including cell-phone only households in the diary sample has been difficult because of a federal law prohibiting random digit dialing to cell phones. Arbitron plans to use an address-based sample frame as the foundation of its cell-phone-only sample, while maintaining the random-digit-dial sample frame for landline households.
Information about cell phone-only households comes, interestingly enough, from the federal Centers for Disease Control and Prevention’s National Center for Health Statistics and its National Health Interview Survey. At the recent consultant fly-in at Arbitron, Dr. Stephen Blumberg of the CDC spoke about how the nationwide trend towards wireless phones presents a growing challenge to conducting phone surveys.
In 1963, one in five households did not have a phone and that made it difficult to conduct telephone surveys in the U.S. and properly represent the population, said Dr. Blumberg. In the ’70s the number of those without a phone dipped and automated call centers for surveyors had their heyday in the ’80s and ’90s.
Now, however, due to the proliferation of cell phones, as of 2007, the CDC survey says 15.8% of U.S. households do not have landlines (and 14.5% of U.S. adults).
The number of households without landlines is growing about 3% per year. Renters are four times more likely than home owners to be cell-phone-only households. Those who have wireless phones only are mostly adults living with roommates, more likely to be male and live in the South and Midwest.
So-called “wireless-only” adults also are more likely to “binge drink, smoke and tell us they’re in good health,” joked Dr. Blumberg, placing a humorous spin on the survey results.
Those who mostly use their cell phones may still keep a landline phone for their security system or DSL broadband.
“We know some of them won’t pick up a [landline] phone if it rings. By age (18-29) half of young adults are wireless only or mostly wireless,” he said.
More about this at www.CDC.gov/nchs/nhis.htm.
