Vorlon, I just read

[CARLHAYDEN]

Point #1

Mellman works for Kerry, any poll showing a Bush lead is fatally flawed.

Bush pollster Matthew Dowd however is of the opinion that all polls showing Bush ahead are methodologically perfect.

But serioulsy, Mellman works for Kerry, what did you expect him to say "Ya, Gallups right, we're getting F$%king killed in Ohio and Missouri, we're thinking of pulling out of those states..."

Point #2

Re Gallup's likely voter screen.

2 months out ANY likely voter screen, by any company, is, well, a crap shoot.

I think we strongly disagree on the efficacy of a voter screen for likely voters.

While (from what I have read of your postings) we agree that "interest" and "following the election closely" techniques constitute a poor screen, I believe that historical voting is a very good screen (i.e. most of those who voted in 2000 and are still alive to vote in 2004 will vote in that election, and most of those who did not vote in 2000 but are legally eligible to vote in 2004 will not vote).

The 'historical' screen is of course NOT perfect, for a number of reasons, mosty prominently, that people LIE about whether they actually voted in the previously cited election.

Adding a demographic screen to the 'historical' screen provides a vast improvement.  

Now, instead of playing football with the matter, lets look at relevant hard data.

First, the highest turnout in a Presidential election in the past 50 years (using VAP) was in 1960 of about 50%.  The lowest turnout about 49% in 1988 (about the same in 1996).  Since the voting age was dropped nationwide to 18 in 1972, the turnout has never exceeded 56% nationwide (of VAP).  So, a screen showing more than 60% of VAP turnout is is a little hard to believe.

Second, the data is very clear that turnout is highly correlated with SES.  This is well established.  The University of Michigan SRC has a large amount of data on this.  So do a number of other sources.

Third, you are correct that polling does become a little more accurate in the last month before the election.  One of the factors is that in most states, voter registration cuts off about a month before the election.  

[CARLHAYDEN]

Ok.

Basically we agree.

It seemed to me that in your previous post (responding to another poster) that screening was pretty iffy.

I agree that on the face of it, pollsters showing a turnout of over 60% of VAP probably have a very poor screen.

Essentially my point was a multi-stage screen.

First, is the respondent registered to vote.  If yes, go to screen two (if no, drop from main sample).

Second, does the respondent say they are likely to vote.
If yes, go to screen three (if no drop from main sample).

Three, did the respondent vote in the last election for the office being polled?  If yes, include in main sample (if no, weight the responses using democraphic information before including in main sample).

I have found the technique to be pretty reliable.

[CARLHAYDEN]

I think the problem is that many firms only use screens one and two.

Adding on screens three and four (in my experience) vastly improves the results.

Let me give you a hypothetical example.

A. You get 'completes' on a survey from 1000 respondents (You've already established that they are all according to their statements, of voting age).

B. Say 876 of the completes claim to be registered voters, but in fact, only 700 are registered to vote (some people honestly think they're registered to vote when they are not, and some people just lie about it because they don't want the interviewer to think they're not good citizens).

C. Of the 876 repondents who went through the first screen,  700 tell you they are likely to vote (when in fact only about 543 will vote).

D. Of the 700 who passed through the second screen,  about 456 will tell you they voted in the previous election for the office in question (I'm using Presidential election figues).  In fact, about 432 of them voted for President in 2004.  The beauty of this is that not too many people will tell a whole series of lies in a short interview.  Besides, the previous questions have allowed them to establish that they are 'good citizens,' and therefor can explain away their non-vote in 2000.

E. Now, if we assume a turnout of 54.3% of the VAP (i.e. 543 respondents), then obviously we have a shortfall of 87 respondents if we solely relied upon the previous screen.  This means that just under 36 per cent of the people who passed all of the screens except the historical voting one are in fact likely to vote.

However, they are not equally likely to vote.  So, you use historical voting demographic data to make an improved projection of the likelihood of voting (SES).

Finally, you fold the 87 likely respondents (as established with this method) in with the 456 who passed the earlier screens.

While this process isn't perfect (polling is as much an art as a science), it does produce far more accurate results than the simplistic methods used by too many pollsters.

[CARLHAYDEN]

Well, that really constitutes an interesting cross national question.

In the United States, only about 54 per cent of the Voting Age Population actually will vote in the Presidential election.

In many european countries, where voting is required by law, turnout runs around 85% of those eligible.

So, projecting who is more likely to vote in the United States is more difficult than projecting who is likely to vote in most european countries.

However, people in the United States and northern europe tend to honestly answer their preferences as to how they actually will cast their ballot in the election, whereas in many other countries the respondents are somewhat less likely to tell you their true voting intent.

[CARLHAYDEN]

I think the problem is that many firms only use screens one and two.

Adding on screens three and four (in my experience) vastly improves the results.

Let me give you a hypothetical example.

A. You get 'completes' on a survey from 1000 respondents (You've already established that they are all according to their statements, of voting age).

B. Say 876 of the completes claim to be registered voters, but in fact, only 700 are registered to vote (some people honestly think they're registered to vote when they are not, and some people just lie about it because they don't want the interviewer to think they're not good citizens).

C. Of the 876 repondents who went through the first screen,  700 tell you they are likely to vote (when in fact only about 543 will vote).

D. Of the 700 who passed through the second screen,  about 456 will tell you they voted in the previous election for the office in question (I'm using Presidential election figues).  In fact, about 432 of them voted for President in 2004.  The beauty of this is that not too many people will tell a whole series of lies in a short interview.  Besides, the previous questions have allowed them to establish that they are 'good citizens,' and therefor can explain away their non-vote in 2000.

E. Now, if we assume a turnout of 54.3% of the VAP (i.e. 543 respondents), then obviously we have a shortfall of 87 respondents if we solely relied upon the previous screen.  This means that just under 36 per cent of the people who passed all of the screens except the historical voting one are in fact likely to vote.

However, they are not equally likely to vote.  So, you use historical voting demographic data to make an improved projection of the likelihood of voting (SES).

Finally, you fold the 87 likely respondents (as established with this method) in with the 456 who passed the earlier screens.

While this process isn't perfect (polling is as much an art as a science), it does produce far more accurate results than the simplistic methods used by too many pollsters.

Vorlon, would appreciate your analysis.

[CARLHAYDEN]

Vorlon,

I repeat my earlier request.

Also, with respect to your site, how much was the contribution qualifier, and where should it be sent?