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On 8/11/2017 1:15 PM, Erik Toren via Marxism wrote:

Hispanic is a big category. I wonder which subgroup of Hispanics has


Public opinion surveys claiming things about Latinos generally would not be worth the paper they're printed on if someone printed them. But the entire field of public opinion polling is in crisis, for the techniques that worked in the 20th Century no longer do. Most of all, people aren't cooperating with surveys

But apart from that, Zogby surveys are systematically biased (in a statistical sense) due to their design. It is a self-selected population skewed towards heavier internet and especially email usage.

Zogby says they're surveying "Likely voters". Likely voters in what election? You may say, well, the next one is November 2018 but that is wrong. My county board of elections had 12 elections scheduled for the current year, one a month. In reality, from among the self-selected participants, Zogby is deciding who merits being counted and whose answers should be discarded as coming from a member of the great unwashed.

The traditional screens for "likely voter" include questions like do you know where your voting place is? Who is running in this election? When did you register to vote? Those really only become significant when the election is very close.

Zogby did not detail its methodology for this survey, but we know they survey by email invitation. A greater proportion of Latinos are Internet users but a higher percentage (than among the general population) have access mostly or exclusively through smartphone, so they use email less.

Although "Hispanic" is now the largest racial/ethnic minority (that the government counts), surveys rarely break out numbers for Latinos, even though they do so for Blacks. That's because they have so few Latinos that actually respond. The response rate among Latinos is lower than for anglos and Blacks even in bilingual phone surveys.

But the truth is the OVERALL response rate is now so low for the population as a whole as to call into question the validity of polling, period. That's why the largest and most prestigious polling organization, Gallup, has stopped doing election polls.

When I first became involved in the field at CNN in 1990, the response rate for phone polls was close to 50%. For the last few years it has been under 10%, according to Pew. For email-invitation surveys, the response rate is even lower.

Zogby says they had 1300 people in their new poll. They do these presidential approval surveys frequently and in July they had 856 and in June, 1031 and at the end of April 876. This raises the obvious question: did the methodology change? Were different numbers of invitations to participate sent out? Or did the response rate vary wildly, so that half again as many people responded now as three or four weeks ago? If so, THAT is probably a more significant data point worth exploring than what they think of Trump.

But we don't know because Zogby only says they send out "thousands" of emails. Nor do they publish a detailed, question-by-question breakdown of results like reputable pollsters do.

And then consider the Latino sub-sample. If they actually got the same percentage as among the 2016 voters (10%) that would have been 130 of the 1300 total respondents. But my experience tells me it was about 2/3rds that number, let's say 90. The MoE with that sample is more than 10%, which means the numbers this survey gives for Latinos are meaningless. Even at 130 they're junk (MoE=8.7%). And the previous surveys that the new Hispanic number is being compared to was 856, so there was no way you could have gotten meaningful percents out of that poll.

BTW under representation of a huge problem because it is not just Latinos. Experience shows polling respondents systematically under represent young people, minorities, and people without a college education. So you take your raw results, and then you look at the demographics you SHOULD have had, based on, for example, census bureau numbers, and weigh the results accordingly. So if you should have had 120 Blacks but actually only had 100 Blacks respondents, you give a "weight" of 1.2 to each Black respondent.

But when it comes to "likely" voters, you define what the target universe looks like, how many Blacks, how many high school graduates. So, are the demographics those of the 2016 presidential or the 2014 off-year electorate? If we're talking about the 2020 electorate, who is the Democrat? Clinton gives you one electorate, Bernie, a very different one.

(This was the big reason Gallup abandoned polling the presidential race. The results depended on the weighing of the various segments of the population, but this was determined not by hard, objective data but a subjective judgment of who would vote. But that in itself is a statement about who is likely to win. )

This cock-and-bull story about Trump support especially among Latinos is typical Zogby. The survey mechanism is junk and not described in detail. The actual complete results are not made available. And then the result numbers are cherry picked, squeezed and massaged, to fit a political and/or business agenda.

Zero transparency and not much more scientific rigor.

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