Down for the Count

Why can’t journalists get their numbers right?

| January-February 1996

Nothing gives a journalistic story more (apparent) credibility than a battery of statistics skillfully deployed. But in a society in which numerical skills are sorely lacking, are journalists giving us numbers we can rely on?

In A Mathematician Reads the Newspaper (BasicBooks, 1995), John Allen Paulos takes lazy reporters to task for underachieving mathematically and thereby reinforcing cultural bias and amplifying public ignorance of important issues. For example, he debunks claims that “blacks in New York City vote along racial lines more than whites do”: “The evidence cited was that 95 percent of blacks voted for (black) mayor David Dinkins, whereas only 75 percent of whites voted for (white) candidate (and victor) Rudolph Giuliani. This assertion failed to take into account, however, the preference of most black voters for any Democratic candidate. Assuming that 80 percent of blacks usually vote for Democrats and only 50 percent of whites usually vote for Republicans, one can argue that only 15 percent of blacks voted for Democrat Dinkins based on race and that 25 percent of whites voted for Republican Giuliani based on race.”

Paulos warns that supposedly scientific pollsters are also likely to feed erroneous numbers to a gullible public (via our snoozing watchdogs of the press). He notes that stories about a 1993 Roper poll suggested that nearly a quarter of Americans doubted the reality of the Holocaust, but it turned out that the figure was a consequence of a badly worded question: “Rephrased, the question elicited the less distressing information that only 1 percent of Americans thought that it was ‘possible [that] ... the Nazi extermination of Jews never happened.’”

Confusing correlation with causation is a common error, Paulos cautions. “Studies have shown repeatedly, for example, that children with longer arms reason better than those with shorter arms, but there is no causal connection here. Children with longer arms reason better because they’re older! Consider a headline that invites us to infer a causal connection: Bottled water linked to healthier babies. Without further evidence, this invitation should be refused since affluent parents are more likely both to drink bottled water and to have healthy children.”

Our big fears are sometimes statistical small potatoes. Paulos suggests casting numbers in a new light to provide fresh perspective. In contrast to the plane crashes that disproportionately dominate the front page, he notes, cigarette smoking kills 400,000 Americans annually—the equivalent of three fully loaded jumbo jets crashing each and every day of the year.

Math properly employed can help journalists shed light on environmental topics, medical reports, and economists’ claims. In the wrong hands, though, it merely clouds the issues. And it seems to be in the wrong hands much of the time. One reason may be widespread misunderstanding of what math is. Paulos cites five major misconceptions: that mathematics is essentially a matter of computation, is strictly hierarchical, is without narrative, is only for the elite, and numbs one to the aesthetic and sensual aspects of life.