America's abandonment of the landline phone in favor of the cellphone is accelerating, but nowhere has it gone further than in Arkansas and Mississippi. The states where the smallest proportion of people depend solely on wireless phones and no landlines: New Jersey and Rhode Island.
About 35 percent of adults in Arkansas and Mississippi have cellphones and lack traditional wired telephones, according to estimates released Wednesday by the federal Centers for Disease Control and Prevention. In New Jersey and Rhode Island, that figure is only 13 percent.
"The answer's obvious. No one has money here," said John N. Daigle, a professor of electrical engineering at the University of Mississippi who has had broad experience in the telecommunications industry. "If they can do without a landline, they'll do it to save money."
That matches the conclusion of Stephen Blumberg, a senior CDC scientist and an author of the survey. Over the years, Blumberg has found that lower-income people are likelier than the better off to only have a cellphone. Younger people and renters are also among the quickest to shed traditional landlines and use only wireless phones.
"They're not a young state and they're a wealthy state, and that's keeping New Jersey at the bottom of the list" of states whose residents rely exclusively on cellphones, Blumberg said.
The latest state-by-state figures, which cover the 12 months through June 2010, are significant. They may mean that changes are needed in how some public opinion polls are conducted, Blumberg said.
As the use of cellphones has grown in recent years, major pollsters have routinely included cellphone users in the people they call randomly. The number of cellphone users they call reflects national cellphone use, but this study suggests that those numbers may need to be adjusted in states with especially high or low cellphone dependence, he said.
In eight states besides Arkansas and Mississippi - mostly in the West - at least 30 percent of adults rely strictly on cellphones. They are Colorado, Idaho, Kentucky, Nebraska, North Dakota, Oklahoma, Oregon and Texas.
At the low end, only six states join New Jersey and Rhode Island in having less than 17 percent of adults use only cells: Connecticut, Delaware, Massachusetts, New Hampshire, Pennsylvania and South Dakota. All but one are in the East.
The exclusive use of cellphones has been growing steadily nationwide, hitting 27 percent of U.S. households in the first half of 2010, an eightfold increase in just six years.
Wednesday's figures showed that the proportion of adults using only cellphones has grown in all 50 states since 2007. Arkansas has had the greatest increase, with 15 percentage points, while New Jersey's 7 percentage point growth brings up the rear.
"That's not surprising to me," Charles Golvin, a telecommunications analyst with the market research firm Forrester Research Inc., said of the coast-to-coast growth. He said people across the country are facing challenges with the weak economy. "It's personal; you know if it's right for you," he added.
Other measurements also highlight how widespread people's dependence on cellphones has become.
The proportion of adults living in households with cellphones - including those that also have landlines - range from 92 percent in Iowa to 48 percent in South Dakota.
In addition, large numbers of adults live in households that get all or most of their phone calls on cellphones - covering families that, for example, have a landline hooked into a computer. The highest proportion is in Texas, where 53 percent of adults are best reached on cellphones, while the lowest is 25 percent in South Dakota.
Blumberg said he was somewhat puzzled by the South Dakota figures, which differed significantly from nearby, similar states.
South Dakota's 16 percent who rely solely on cellphones is about half North Dakota's rate. In addition, 51 percent in South Dakota reported having only landlines and no cellphones - well above the 37 percent in the next highest state anywhere in the nation, Montana.
Steve Kolbeck, chairman of South Dakota's Public Utilities Commission, said he believes his state's low reliance on cellphones reflected its vast rural areas, though nearby states have similar topography and a higher dependence on wireless phones.
"It really surprises me," Kolbeck said. "For as mobile as people are in South Dakota and as remote as we are? I mean, everybody and their dog seems to have a cellphone, but they must be keeping their landline as that backup."
The estimates are based largely on data from the National Health Interview Survey, conducted by the CDC, in which interviews with 109,187 households have been conducted over the past 3 1 / 2years.
Also used are statistics from the Census Bureau's American Community Survey between 2006 and 2009 and information from listed telephone directories. The figures are then blended to produce a single estimate.