Monday, January 21, 2008
Land line phones dying
Research Live reports that evidence from the National Health Interview Survey put the incidence of cell-only homes at more than one in eight – or 28 million adults – for the first six months of 2007. It's probably considerably higher, because those numbers are up quite a bit from earlier.
The percentage of American adults in cellphone-only homes shot up from 7.7% to 11.8% between 2005 and 2006, reported an earlier story.
Not surprisingly, this is skewed by age: "Based on estimates from the US Bureau of the Census’ 2004 Current Population Survey, around 7% of US homes are believed to be cellphone-only, rising to 20% for persons aged 15-24."
This matters a lot in the marketing research business, although there's a brave face put on it.
"Although countless studies by Gallup and others, including the Pew Research Center, suggest the exclusion of wireless households does not cause any significant impact on survey data, it has prompted fears that young, low income and ethnic minorities could be under-represented, as they are the demographic groups most likely to be ‘cutting the cord’."
So, the Gallup organization is adjusting. "Gallup Poll editor-in-chief, Frank Newport said the addition of cell-only homes was “a complex and costly modification” in methodology.... In addition to sampling from the traditional database of all landline telephone exchanges, Gallup now also adds in sampling from a new database of all cellphone telephone exchanges in the country... We screen for those individuals using cellphones who report not having a landline, and then interview a random sample thereof. We then weigh into the sample a proportionate percentage of these interviews conducted via cell phone.”
"As well as the sampling issues, researchers calling cellphones also have to contend with the problem of number portability, which makes it hard to match a telephone number to a specific geographic area, as well as a law prohibiting the use of auto-diallers when calling cellphones, meaning all numbers must be manually dialed.
"Cellphone users in the US are also typically charged for calls received, so agencies would expect to pay compensation – on top of an incentive, perhaps – for the costs an interviewee incurs in taking part in a survey."
at 8:19 PM