Forest Nelson and several academics from the University of Iowa were sitting down to lunch in March of 1988, just after the Michigan Democratic caucus. Michael Dukakis had been predicted to beat Jesse Jackson by a landslide. Instead, Jackson easily pulled off a startling upset. “One of the other two guys said, ‘Boy, if the futures markets in Chicago did as bad a job of predicting the November price of corn as those opinion polls did of predicting the very next day’s election, then those markets wouldn’t exist,’” recalled Nelson, an economics professor still at the university. ... Read More
On Immigration Polls, a Lot of People Lie
June 5, 2011 • By • Leave a Comment
A Gallup survey taken last year found 45 percent believe immigration in the United States should be decreased, compared to 17 percent saying it should be increased and 34 percent saying it should be kept at present levels. But should such figures be taken at face value? University of California, Berkeley, sociologist Alexander Janus argues not. Using a polling technique designed to uncover hidden bias, he concluded about 61 percent of Americans support a cutoff of immigration. Janus, who published his findings in the journal Social Science Quarterly, argues that "social desirability pressures" ... Read More
Understanding Popular Uses of Percentages
April 30, 2011 • By • Leave a Comment
Four New Jersey women in March accused the Campbell Soup Company of misleading customers with claims of lower sodium levels in its "25% Less Sodium Tomato Soup." Whether the soup has more or less sodium than regular versions is not for me to investigate. I want to focus on the "25% less" phrase — a type of claim we see regularly in ads and new product labels — and in the process provide some numerical literacy skills to our arsenal of skeptical thinking tools. In an age when quantitative thinking is at a premium and "innumeracy," as cognitive scientist Douglas R. Hofstadter termed it, ... Read More
Questioning Questions in Evaluating Polls
May 27, 2010 • By • 2 Comments
Recently a conservative organization's solicitation letter (aka junk mail) arrived in my mailbox pleading for funds to "clean up television." I strongly agree that there's much on TV that I would like to see changed, but my list would primarily be to eliminate stupid reality shows and idiotic cable news commentators interrupting each other in shouting matches. This letter had something else in mind. Attached to the donation card was an "official poll" asking several questions including: "Are you in favor of television programs which major in gratuitous violence such as murder, rape, ... Read More
Lies of a Cell
May 25, 2010 • By • 2 Comments
Pollsters have known for some time that the 40-year-old process of calling someone's home phone and quizzing them about Candidate X or Issue Y has a small but growing bug in reflecting reality — some people, and more importantly, some definable groups, have abandoned landlines for cell phones. (Of course there were always people with no phones not getting polled, but that's another story.) In 2007, the Pew Research Center and The Associated Press teamed up to ask what was missing from national surveys, and answered it was cell phone-only users. At that time 12.8 percent of U.S. ... Read More
The Perils of the Poll Position
July 24, 2008 • By • Leave a Comment
Everyone's a poll cat in this turbocharged election year, trying to divine an outcome we won't realize until late Nov. 4 — if then. All through the interminable series of primary elections, it was who's ahead, who's behind, who's gaining, who's slipping — and why. A dozen or more polling firms — several associated with major networks, newspapers or magazines — were pleased to answer those questions for you, day by day, week by week, with dubious accuracy. Now that the two multicandidate fields are down to their "presumptive" nominees, it's head-to-head combat for the next four ... Read More
