Why do Clinton and Trump do better in robo-call polls and worse in live cell/landline phone polling?

[Attorney in Texas]

This is a documentable phenomenon.

Here is the New Hampshire polling according to ALL the robo-call polls considered by either RCP or Huffington Post's Pollster:



Here is the New Hampshire polling according to ALL polling considered by either RCP or Huffington Post's Pollster except with the robo-call polls excluded:



The inclusion of robo-call polling in the pollster aggregation models makes the New Hampshire race seem like a closer race than the impression you would draw from all the other polling. The phenomenon also holds true in Iowa, where the robo-call polls make Clinton's lead seem bigger than other polling indicates. This same phenomenon also favors Trump in Iowa and New Hampshire in the similar manner that it favors Clinton.

Any thoughts about the cause of this phenomenon?

[RandySF]

1. One theory I read years ago.

Respondents feel less shy about stating their true choices.

[Attorney in Texas]

3. When 538 discussed this polling phenomenon, they considered that people might be embarrassed to

admit the preference in a live phone poll so that might explain the difference (538 discussed possibilities but came to no conclusions).

I think that is not likely because while that might make some sense with Trump (people feeling embarrassed to tell a live interviewer that they support someone who has so many trollish policies) but that does not seem to apply to Clinton (I'm a Sanders supporter but I cannot see why anyone would be embarrassed to support Clinton).

[RandySF]

4. I can only speak for myself

But I've reached the point where I don't take the time to answer surveys (we get a lot), but I'm more likely to push a button.

[Attorney in Texas]

5. I get that, but why would Clinton supporters feel that way more than O'Malley or Sanders supporters?

[RandySF]

6. Isounds like a good future research paper.

[Renew Deal]

2. There was an article about this in regards to Trump

Basically educated people won't admit to supporting him. So the theory is that his polls are stronger than the numbers show. Could this be bad for him in IA?

http://www.democraticunderground.com/10027491134