What’s Missing from National RDD Surveys? The Impact of the Growing Cell-Only Population
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.