SurveyUSA polls the Governor's race again

SurveyUSA (11/10, 10/28 in parentheses):

Mark Dayton (D): 45 (39)
Tom Emmer (R): 44 (38)
Tom Horner (I): 9 (13)
Undecided: 1 (6)
(MoE: ±3%)

KSTP decided that it would be fun to resurvey the Minnesota Governor's race, you know, now that we know the outcome and everything.

What they found was confirmation of what happened and although we have actual ballots to tell us Mark Dayton won, the ballots don't tell us about some of the underlying numbers that this poll sheds a little light on.

Polling in Minnesota Governor's races; part 2

This is part two of a series I began yesterday. Part one can be found here.

In yesterdays post I went through some past Minnesota elections and the polling associated with them. What I found is that polling in Minnesota Governor's races has exhibited a consistent DFL bias, by between 4-5 points on average.

I concluded the post with this:

There are two possibilities; either the polls themselves are wrong, or the polls are right and the GOP candidate is receiving a wave of support at the end of the race.

It's those possibilities that I will deal with today.

Polling in Minnesota Governor's races; part 1

This was intended to be one post but quickly developed into a monster that just had to be segmented. While I am certainly not above splitting posts up simply for the sake of more posts, that is not the case in this instance.

The following comment from ldc sums it up:

I haven't seen a good explanation for why they were so far off, not just MPR/Humphrey but others too. At least in the Nevada senate race, they could explain the difference in pollster vs real election results by the Latino vote and whether the pollsters gave a Spanish language option. So what is the answer here??

She is right in that there doesn't appear to be an easy explanation like in some other states for the inaccuracies of some of the Minnesota Governor's race polls. I have advanced the argument before that errors in 2006 polling was due to late breaking events in that race that caused undecided voters to break heavily for Tim Pawlenty.

What about 2002 than? In that year the pollsters correctly predicted a Pawlenty win, but missed the final margin by about the same amount as in 2006 and 2010, 5 points. On the other hand polling in Minnesota Senate races, and Presidential races, has been rather accurate. Is there something about Minnesota Governor's races that makes polling them especially difficult?

Who's polling The Minnesota Governors race

Only four pollsters; Rasmussen, SurveyUSA, Princeton Survey Research Associates (PSRA) and Humphrey Institute, have polled the Minnesota Governors race this year and with under a month left before the election it's unlikely that many more will jump in. In 2006 these same four pollsters (StarTribune had in-house polling in 2006, now they contract with PSRA) were joined by Mason-Dixon, St. Cloud St. and Polimetrix, so it's possible that one of them or someone else entirely will drop a poll on us but for now we're just going to look at who's been polling it so far.

A few notes on terms and formatting first.

PIE is Pollster Induced Error, a metric developed by Nate Silver, it's a measure of how much error, above average, a pollster contributes based on an analysis of past polls.

Past election results are listed as follows:
Race Polled: Last polling result (Actual results) Margin Difference
The margin difference is the polling margin minus the actual margin.

The Pollsters Dilema

--or--

What's up with SurveyUSA's 18-34 polling and other observations

This post is the result of a back and forth I had with Aaron Klemz at The Cucking Stool in the comments of his post about the age gap in the most recent SurveyUSA poll of the Minnesota Governor's race. This was my initial comment:

This has been a trend for SurveyUSA all year and not just in Minnesota. I find these numbers hard to believe and suspect they have more to do with a flaw SurveyUSA's methodology when it comes to young voters. Perhaps it's an issue with cell phones perhaps it's the fact that they are an automated pollster, who knows.

The more I've thought about this the more I think it's an issue deserving of discussion outside of a comment thread.