by Scott Keeter (Pew Research Center), Courtney Kennedy (University of Michigan and Pew Research Center), April Clark (Pew Research Center), Trevor Tompson (The Associated Press), and Mike Mokrzycki (The Associated Press)
The number of cell-phone-only households has continued to grow — 12.8% of all households by the end of 2006, according to the National Health Interview Survey. While the noncoverage problem is currently not damaging estimates for the entire population, a study finds evidence that it does create biased estimates on certain variables for young adults, 25% of whom are cell-only.
