October 17, 2008
I JUST KNOW THAT THIS TIME THE NON-VOTERS WILL VOTE!:
Some Surveys Indicate Tighter Presidential Race: Differences in Predicting Outcome Result From How Pollsters Gauge Voter Turnout and Weight Party Affiliation (NICK TIMIRAOS, 10/17/08, Wall Street Journal)
Differences over how to accurately gauge party affiliation also help account for the discrepancies. Some pollsters argue polls should be statistically "weighted" so that their results achieve a partisan composition that reflects long-term national averages -- particularly if a poll shows that one party gets an unusually large share among the respondents, compared with past elections.Posted by Orrin Judd at October 17, 2008 6:29 PMPollster Scott Rasmussen, for example, weights current polls so that Democrats outnumber Republicans by a 39.3% to 33% margin, while pollster John Zogby adjusts polls so that Democrats account for around 38% of the electorate and Republicans, 36%. So even if a particular sample of calls shows different ratios, the pollsters adjust to fit that formula.
"What troubles me is when I see some of my colleagues have 27% of the respondents that are Republicans. That's just not America, period," says Mr. Zogby, whose polls have shown Sen. Obama with a lead ranging from two to six points this month. He argues that while party affiliation fluctuates over time, it doesn't change "day-to-day, and it never fluctuates by eight points in a short time period."
Other pollsters argue that polls should use whatever partisan mix results from a particular survey rather than arbitrarily establishing party affiliation weights. "How do you know that's right? I mean, they're making up numbers," says Susan Pinkus, who conducts the Los Angeles Times-Bloomberg poll, which isn't weighted. In this week's poll, the respondents were 34% Democratic and 26% Republican.
