Most Americans Live in Wireless-Only Households

From CDC's National Center for Health Statistics:

Since 2007, the National Health Interview Survey (NHIS) Early Release Program has regularly released preliminary estimates of the percentages of adults and children living in homes with only wireless telephones (also known as cellular telephones, cell phones, or mobile phones). These estimates are the most upto-date estimates available from the
federal government concerning the size and characteristics of this population.

In January 2019, the NHIS launched a redesigned questionnaire. Among other changes, it is now possible to estimate the percentage of adults who live in wireless-ly households and have their own wireless telephone (wireless-only adults).

Estimates in this report are based on the first six months of 2019. During this time period, 59.2% of adults and 70.5% of children lived in wireless-only households.
In comparison, a slightly smaller percentage of adults were wireless-only adults (58.4%). Four in five adults aged 25–29 (80.2%) and aged 30-34 (78.3%), and three in four adults renting their homes (75.1%), were wireless-only adults.

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Many health surveys, political polls, and other types of research are conducted using random-digit-dial (RDD) telephone surveys. Most survey research organizations include wireless telephone numbers when conducting RDD surveys. If they did not, the exclusion of\ households with only wireless telephones (along with the small proportion of households that have no telephone service) could bias results. This bias— known as coverage bias—could exist if there are differences between persons with and without landline telephones for the substantive variables of interest.

Polling Problems

 J. Patrick Coolican at the Minneapolis Star Tribune spoke to political scientist Steve Schier about polls:

If you ask a one-sided question, it may turn into what’s called a “push” question, which is lingo for a biased inquiry that is seeking to drive public opinion, not measure it. So for instance, “Do you believe the president is guilty of impeachable offenses?” You’ve already introduced his guilt into the question.

Here’s an alternative: Which do you agree with: The president is guilty of impeachable offenses or this an unfair partisan attack?

These two-sided questions are longer and more difficult to write, which means more expensive.

Questions about race can be problematic. Schier said political science has shown that the perceived race of the questioner can affect the response on race issues.

Then there’s the cellphone problem: What percentage of respondents should be on cellphones? Polling cellphones is much more expensive.

And what portion of respondents comes from communities where English is a second language?

Polls also are not effective at measuring the public’s intensity on an issue.

A respondent might say she favors more gun control, but that doesn’t measure her willingness to go out on a snowy day and vote on that issue — and that issue alone.
“Intensity drives politics,” Schier said.

He cites the work of political scientist David RePass, who has shown that by asking the same set of respondents the same questions over a period of months, we find very few people have consistent views.

“It means a lot of people aren’t thinking much about the issues,” Schier said.
The public is also prone to wide swings in the face of major news events.

Yes, the media are partly to blame. But Schier said the public is also responsible: “The voice of the public is not always the voice of God. God is a little more alert.”

Wireless Nation 2017

From the National Center for Health Statistics:

Preliminary results from the July– December 2017 National Health Interview Survey (NHIS) indicate that the number of American homes with only wireless telephones continues to grow. More than one-half of American homes (53.9%) had only wireless telephones (also known as cellular telephones, cell phones, or mobile phones) during the second half of 2017— an increase of 3.1 percentage points since the second half of 2016. More than 70% of adults aged 25-34 and adults renting their homes were living in wireless-only households. This report presents the most up-to-date estimates available from the federal government concerning the size and characteristics of this population.

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 Three in four adults aged 25–29 (75.6%) and aged 30-34 (73.3%) lived in households with only wirelesstelephones. These rates are greater than the rate for those 18–24 (67.1%). The percentage of adults living with only wireless telephones decreased as age increased beyond 35 years: 64.5% for those 35–44; 48.1% for those 45–64; and 26.4% for those 65 and over.

Nearly four in five adults living only with unrelated adult roommates (77.5%) were in households with onlywireless telephones. This rate is higher than the rates for adults living alone (59.7%), adults living only with spouses or other adult family members (45.2%), and adults living with children (60.5%).

More than seven in ten adults living in rented homes (72.0%) had only wireless telephones. This rate is significantly higher than the rate for adults living in homes owned by a household member (44.6%).

Adults living in poverty (68.1%) and near poverty (58.1%) were more likely  than higher income adults (53.1%) to be living in households with only wireless telephones. (Footnote 3 in Table 2 gives definitions of these categories.)

Hispanic adults (65.6%) were more likely than non-Hispanic white (50.2%), non-Hispanic black (52.3%), or non-Hispanic Asian (53.4%) adults to be living in households with only wireless telephones.

Adults living in the Midwest (55.6%), South (56.7%), and West (56.9%) were more likely than those living in the Northeast (39.3%) to be living in households with only wireless telephones.

Cellular-Only Households and Polling Problems

A release from CDC:

Preliminary results from the January–June 2015 National Health Interview Survey (NHIS) indicate that the number of American homes with only wireless telephones continues to grow. Nearly one-half of American homes (47.4%) had only wireless telephones (also known as cellular telephones, cell phones, or mobile phones) during the first half of 2015—an increase of 3.4 percentage points since the first half of 2014. More
than two-thirds of all adults aged 25-34 and of adults renting their homes were living in wireless-only households. This report presents the most up-to-date estimates available from the federal government concerning the size and characteristics of this population.

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Many health surveys, political polls, and other types of research are conducted using random-digit-dial (RDD) telephone surveys. Despite operational challenges, most major survey research organizations include wireless telephone numbers when conducting RDD surveys. If they did not, the exclusion of households with only wireless telephones (along with the small proportion of households that have no telephone service) could bias results. This bias—known as coverage bias—could exist if there are differences between persons with and without landline telephones for the substantive variables of interest.

At FiveThirtyEight, Nate Silver writes:

One of the biggest fears of using Internet polls is that they’re not representative of the electorate. You can weight to get rid of some disparities in a volunteer sample — if you have too few elderly respondents, for example, then the elderly respondents youdo have get more weight in the average. But weighting may not be enough; the type of older Republican who signs up for an Internet poll may differ politically from the older Republican who answers only a telephone poll. Although this isn’t a big deal in general elections in which party identification tends to determine vote choice, it’s unclear how well Internet polls that weight by party identification will do in the primary.4
A recent YouGov poll sponsored by the University of Massachusettsconfirmed these fears. UMass decided to match the YouGov likely voters to the list of active registered voters to see whether they could be confirmed as registered to vote. Among confirmed voters, Trump did 3 percentage points worse. Meanwhile, the other candidates did, on net, 10 percentage points better. Thus, even though there were fewer undecided respondents among those confirmed as registered to vote — so, all else being equal, every candidate’s vote share should have increased — Trump lost ground.

Automated phone polls, of course, can call actual voters through a list sample. They can’t, however, call cellphones (it’s the law). In order to make up for this deficiency, pollsters who perform them often use Internet panels, which themselves may not be representative.

Survey Nonresponse

In a Pew interview, Scott Keeter talks about response rates in surveys:

The potential for what pollsters call “nonresponse bias” – the unwelcome situation in which the people we’re not reaching are somehow systematically different from the people we are reaching, thus biasing our poll results – certainly is greater when response rates are low. But the mere existence of low response rates doesn’t tell us anything about whether or not nonresponse bias exists. In fact, numerous studies, including our own, have found that the response rate in and of itself is not a good measure of survey quality, and that thus far, nonresponse bias is a manageable problem.

For example, our 2012 study of nonresponse showed that despite declining response rates, telephone surveys that include landlines and cellphones and are weighted to match the demographic composition of the population (part of standard best practices) continue to provide accurate data on most political, social and economic measures. We documented this by comparing our telephone survey results to various government statistics that are gathered with surveys that have very high response rates. We also used information from two national databases that provide information about everyone in our sample – both respondents and non-respondents – to show that there were relatively small differences between people we interviewed and those we were unable to interview.
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We are obtaining nearly identical response rates on landline phones and cellphones. However, it takes considerably more interviewer time to get a completed interview on a cellphone than a landline phone, because cellphone numbers have to be dialed manually to conform to federal law. In addition, many cellphones are answered by minors, who are ineligible for the vast majority of our surveys. Unlike a landline, we consider a cellphone a personal device and do not attempt to interview anyone other than the person who answers.

Polling Problems

At The New York Times, Cliff Zukin explains that election polls have become increasingly unreliable because of rising cellphone usage and declining response rates.

In terms of speed, the growth of cellphones is like few innovations in our history. About 10 years ago, opinion researchers began taking seriously the threat that the advent of cellphones posed to our established practice of polling people by calling landline phone numbers generated at random. At that time, the National Health Interview Survey, a high-quality government survey conducted through in-home interviews, estimated that about 6 percent of the public used only cellphones. The N.H.I.S. estimate for the first half of 2014 found that this had grown to 43 percent, with another 17 percent “mostly” using cellphones. In other words, a landline-only sample conducted for the 2014 elections would miss about three-fifths of the American public, almost three times as many as it would have missed in 2008.

Since cellphones generally have separate exchanges from landlines, statisticians have solved the problem of finding them for our samples by using what we call “dual sampling frames” — separate random samples of cell and landline exchanges. The problem is that the 1991 Telephone Consumer Protection Act has been interpreted by the Federal Communications Commission to prohibit the calling of cellphones through automatic dialers, in which calls are passed to live interviewers only after a person picks up the phone. To complete a 1,000-person survey, it’s not unusual to have to dial more than 20,000 random numbers, most of which do not go to actual working telephone numbers. Dialing manually for cellphones takes a great deal of paid interviewer time, and pollsters also compensate cellphone respondents with as much as $10 for their lost minutes.

THE best survey organizations, like the Pew Research Center, complete about two of the more expensive cellphone interviews for every one on a landline. For many organizations, this is a budget buster that leads to compromises in sampling and interviewing.

The second unsettling trend is the rapidly declining response rate. When I first started doing telephone surveys in New Jersey in the late 1970s, we considered an 80 percent response rate acceptable, and even then we worried if the 20 percent we missed were different in attitudes and behaviors than the 80 percent we got. Enter answering machines and other technologies. By 1997, Pew’s response rate was 36 percent, and the decline has accelerated. By 2014 the response rate had fallen to 8 percent. As Nate Silver of fivethirtyeight.com recently observed, “The problem is simple but daunting. The foundation of opinion research has historically been the ability to draw a random sample of the population. That’s become much harder to do.”

Cell Phone Privacy

At SCOTUSBlog, Lyle Denniston writes of Riley v. California:

Treating modern cellphones as gaping windows into nearly all aspects of the user’s life and private conduct, the Supreme Court on Wednesday unanimously ordered police to get a search warrant before examining the contents of any such device they take from a person they have arrested. Seeing an individual with a cellphone is such a common thing today, Chief Justice John G. Roberts, Jr., wrote, “the proverbial visitor from Mars might conclude they were an important feature of human anatomy.”

The Court rejected every argument made to it by prosecutors and police that officers should be free to inspect the contents of any cellphone taken from an arrestee. It left open just one option for such searches without a court order: if police are facing a dire emergency, such as trying to locate a missing child or heading off a terrorist plot. But even then, it ruled, those “exigent” exceptions to the requirement for a search warrant would have to satisfy a judge after the fact.

The ruling was such a sweeping embrace of digital privacy that it even reached remotely stored private information that can be reached by a hand-held device — as in the modern-day data storage “cloud.” And it implied that the tracking data that a cellphone may contain about the places that an individual visited also is entitled to the same shield of privacy.

The Court’s ruling drew some suggestions by Justice Samuel A. Alito, Jr., to narrow its scope, but it did not accept those. The result was the broadest constitutional ruling on privacy in the face of modern technology since the Court’s ruling two Terms ago limiting police use of satellite-linked GPS tracking of a suspect’s movements by car.

From the opinion of the Court:

We cannot deny that our decision today will have an impact on the ability of law enforcement to combat crime. Cell phones have become important tools in facilitating coordination and communication among members of criminal enterprises, and can provide valuable incriminating information about dangerous criminals. Privacy comes at a cost.

Or as Charlton Heston said in Touch of Evil, " A policeman's job is only easy in a police state."

Polling Problems

Our chapter on public opinion discusses the challenges facing pollsters.  Several recent articles touch on this subject.

At National Journal, Steven Shepard looks at declining response rates (see a May post) and increasing numbers of cell-only households

Former Democratic pollster Mark Blumenthal, cocreator of the site Pollster.com, examined a number of Gallup polls earlier this year. Blumenthal found that Gallup registers lower approval ratings and ballot-test performances for President Obama than other survey houses—differences that are small but statistically significant.

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Gallup Editor in Chief Frank Newport defended his methodology in the article and in an interview withNational Journal. “One of the biggest changes in recent years, even as our response rates go down, we have millions of people, tens of millions who are desperate to give their opinion,” Newport said.

Incoming AAPOR President Paul Lavrakas said in a telephone interview with NJ that phone polling is “nowhere near dead, nor do I expect it to be dead for several decades. I don’t see that anytime soon we’re going to stop using random-digit-dial surveys in America,” he added.
Lavrakas also said that one reason telephone polling about elections remains fairly accurate is that the same individuals who are more willing to be surveyed also vote more often.

John Harwood writes at The New York Times:

Bill McInturff, a Republican pollster, and Peter Hart, his Democratic counterpart, who conduct the NBC News/Wall Street Journal poll, proved the point in their latest poll, conducted July 18-22, when they increased the proportion of respondents who rely exclusively on cellphones to 30 percent from 25 percent. To home in on them, the pollsters ended calls answered on cellphones if the respondents said they also had land lines.

Their findings affirmed arguments that “cell only” Americans have significantly different, and more Democratic, political views than those with land lines. Over all, the poll showedMr. Obama leading Mr. Romney by 49 percent to 43 percent — providing a confidence-boosting talking point for Democrats and provoking sharp criticism from Republicans.

Scott Rasmussen, who owns an independent polling firm, approaches the “cell only” problem differently, as he must by law. His Rasmussen Reports conducts surveys through automated dialing, which under Federal Communications Commission rules is permitted for land lines but not cellphones.

So in Mr. Rasmussen’s polls, online interviews account for 15 percent to 20 percent of each survey, which he figures helps him reach the same kinds of voters, especially younger ones, in the “cell only” category. The result he reported the morning of July 25, a few hours after the NBC News/Wall Street Journal poll was released, was strikingly different: Mr. Romney had 47 percent, and Mr. Obama 44 percent.

“Nobody has the answers,” Mr. Rasmussen said of different approaches to the issue. “We’re all experimenting with the same thing. How do you reach people in a way they communicate?”

At The Hill, David Hill adds:

The unique challenges of 2012 don’t stop with cellphones. We’ve always known that the hardest thing to do in polling is predict whether a respondent will actually vote or not. Frankly, asking voters directly is the least effective means of making that judgment. Past research has demonstrated that the best ways to judge likely turnout are based on facts gleaned from a voter’s recorded history. How long has someone been registered to vote at his or her current address? (The longer, the better, for turnout.) And did he or she vote in the last election of the same type, in this case the 2008 election? A potential problem using these criteria in 2012 is that 2008 brought out hordes of new voters who seemed mostly motivated by anti-Bush sentiment and the pro-change imagery of Barack Obama.

Is there anything to give us assurance that the new voters of 2008 will return in 2012, like the models say they should?

I am starting to see uneven evidence for this. In some states, like California, they might. In other states, say, Iowa, they might not. So a lot of pollsters could get fooled on turnout.

Cell Phones, Landlines, and Public Opinion

Our chapter on public opinion and political participation describes the challenges of getting accurate measure of public sentiment. One problem is that a growing number of voters do not have landlines at home, only cellular phones. Pollsters may not use automatic dialers to make calls to cellular phones, so it is most costly to reach them (p. 249). Pollsters may be tempted to save money by skipping cellular phones, but a new Pew study shows that landline-only polls produce distorted results.

The number of Americans who rely solely or mostly on a cell phone has been growing for several years, posing an increasing likelihood that public opinion polls conducted only by landline telephone will be biased. A new analysis of Pew Research Center pre-election surveys conducted this year finds that support for Republican candidates was significantly higher in samples based only on landlines than in dual frame samples that combined landline and cell phone interviews.

The difference in the margin among likely voters this year is about twice as large as in 2008.

Across three Pew Research polls conducted in fall 2010 -- conducted among 5,216 likely voters, including 1,712 interviewed on cell phones -- the GOP held a lead that was on average 5.1 percentage points larger in the landline sample than in the combined landline and cell phone sample.

In six polls conducted in the fall of 2008, Barack Obama's lead over John McCain was on average 2.4 percentage points smaller in the landline samples than in the combined samples.

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Cell phones pose a particular challenge for getting accurate estimates of young people's vote preferences and related political opinions and behavior. Young people are difficult to reach by landline phone, both because many have no landline and because of their lifestyles. In Pew Research Center surveys this year about twice as many interviews with people younger than age 30 are conducted by cell phone than by landline, despite the fact that Pew Research samples include twice as many landlines as cell phones.

According to the latest estimates from the National Center for Health Statistics, in the second half of 2009, 38% of 18 to 24 year olds and 49% of 25 to 29 year olds lived in households that had no landline. And research has shown that people younger than age 30 who are cell phone only can have different behaviors and attitudes than those who are reachable by a landline phone. [emphasis added]

Cell Phones and Polls

In our chapter on public opinion and political participation, we discuss a problem facing pollsters. They hesitate to call respondents on cell phones because the law forbids them to use automatic dialers for such calls. But if they take polls only via landlines, they will miss many people. A new article in Public Opinion Quarterly confirms this point:

We first look at the basic incidence of cell-phone-only voters in the exit poll sample in 2008 compared to 2004. The proportion of Election Day voters who live in cell-only households nearly tripled over four years, to 19.9 percent in 2008. This is similar to the finding of the general population National Health Interview Survey, which found 20.2 percent of households had no landline but at least one wireless telephone in the second half of 2008. Another 4.1 percent of Election Day voters reported in the exit poll that their household had no telephone service at all, indicating that pre-election polls using only landline samples failed to cover about 24 percent of the Election Day electorate.