Saturday, October 25, 2008

Voter Surveys and Racial Bias

Thomas Riggins

An article in the October 10, 2008 issue of SCIENCE (Vol. 322, No. 5899) by Jennifer Couzin asks "Do Voter Surveys Underestimate the Impact of Racial Bias? " Her article does not give a clear answer. The reason she cannot arrive at a clear answer is that the polls themselves are so ful ofl biases that they cannot isolate racial bias separately.

She does pose a good question: have the polls "been skewed by an inability to detect racial bias?" Some pollsters think Obama's poll numbers may be off by 6% due to bias but they cannot tell if the polls are or are not reflective of the bias. In other words, its just a guess.

Couzin tells us this bias is called the "Bradley effect" after L.A. mayor Tom Bradley who lost his 1982 bid to be governor of California even though he was ahead in the polls. The assumption is that because he was Black an unexpressed bias cropped up in the election that had not revealed itself in polls.

The article reports that Harvard political scientist Daniel Hopkins, after analyzing every race for the Senate or for a governor from 1989 to 2006, concluded that there was no evidence for the "Bradley effect" after 1996. He doesn't expect race to be a big factor in the 2008 election.

However, Couzin reports that the president of the Pew Research Center, a major polling outfit, (Andrew Kohut) fears that because of "reluctant respondents" [people who don't like to take part in polls] the polls don't really have a representative sample of the population. Studies have shown that reluctant responders are more likely to be racially biased. The Obama lead may not really be there in close polls. Suppose we gave McCain the benefit of the 4% margin of error and the 6% bias drop-- he would have 10 points, maybe 14 points, to add to his poll numbers whenever there is a comparison with Obama. This is a worse case scenario but it is a possibility.

Next the article mentions Michael Lewis Beck who teaches political science at the University of Iowa. He has factored racial basis into his voting model and thinks Obama will win the popular vote, Couzin says, but lose in the electoral college.

Two graduate students in sociology at NYU also did some model building based on racial bias, which they found to be about 16%. The students, Brian McCabe and Jennifer Heerwig, think they got a bigger bias number because the respondents had "greater privacy" (bias is more openly expressed in more private situations). They did their survey over the internet.

However, they should have read, or if they did, heeded, David W .Moore's new book THE OPINION MAKERS: AN INSIDER EXPOSES THE TRUTH BEHIND THE POLLS. Moore points out that the internet polls draw on an unrepresentative sample of the American people, one that seems to be "disproportionately white, male, young, better educated, techno-oriented, and, apparently, conservative." It is impossible to tell from the SCIENCE article how representative the NYU student's group was and consequently how trustworthy their results.

Last, but not least, Couzin, reports on the findings of James Campbell, a political scientist at the University of Buffalo, who predicts that the popular vote, based on his studies, will go to McCain.

So we can't answer the question with which the article opened. But we should bear in mind this. There is already considerable evidence that the Republicans are engaging in voter suppression and intimidation, electronic vote rigging, and inflaming of racial passions and attitudes. One only has to look at the number of Troglodytes turning up at McCain-Palin rallies to be convinced of this. If this election, as have the last two, is stolen from the American people, you can be sure the media and the powers that be will be explaining that the illusion of an Obama victory was due to faulty polls and the "Bradley effect."

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