"Pollsters face a growing obstacle in gathering Americans’ opinions: getting people to answer their calls. The proportion of people called who answer the survey -- in pollster jargon, the "response rate" -- has dropped dramatically over the last few decades as Americans have changed how they interact with the world.

The proliferation of text messages, emails and social media is relegating unsolicited phone calls mostly to the realm of telemarketing, so it’s no surprise that fewer people are inclined to talk on the phone with a stranger. Even worse for pollsters, landline telephones, which are quicker and cheaper to call, have been steadily disappearing over the last 20 years. Almost half of the American population is now solely reliant on mobile phones..."