Wireless-only households are spreading. In the most recent National Health Interview Survey (July – December 2011) from the CDC, the data confirms an ever-increasing trend in the US of households that only have wireless phones. In the second half of 2011, a third of households were wireless-only, a 7.5% increase over the first part of the year.
Hispanics and young adults ( 25 – 29 years old) are over-represented in these households. Consider this information when designing samples for phone surveys to minimize coverage error.
Unfortunately, including cell phones in phone surveys’ samples is still an expensive undertaking. If you can’t afford it, at least be aware of the potential coverage error you will have by not including cell phones in your sample.
Check this infographic with some of the key demographics of households going wireless all the way.