To top it off, a perennial election polling problem, how to identify "likely voters," has become even thornier. Today, a majority of people are difficult or impossible to reach on landline phones. One 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.
The second unsettling trend is rapidly declining response rates, reaching levels once considered unimaginable. In the late 1970s, pollsters considered an 80 percent response rate acceptable, but by 2014 the response rate has fallen to 8 percent. "Our old paradigm has broken down, and we haven't figured out how to replace it," concludes Zukin. "In short, polls and pollsters are going to be less reliable. We may not even know when we're off base. What this means for 2016 is anybody's guess."
The research was carried out at Birmingham, London, Leicester and Manchester schools before and after bans were introduced (PDF). It factored in characteristics such as gender, eligibility for free school meals, special educational needs status and prior educational attainment. "Technological advancements are commonly viewed as increasing productivity," write Louis-Philippe Beland and Richard Murphy. "Modern technology is used in the classroom to engage students and improve performance. There are, however, potential drawbacks as well, as they could lead to distractions."