I've been biting my tongue on Mark Penn's new book Microtrends, as In These Times had asked me to review it for them. Today, the review went live, which is a relief. In short: The book is utterly fascinating. Not for how good it is, but for how bad. And not bad in that I disagree with it . Bad in that it is, methodologically, almost astonishingly sloppy. If this is how Mark Penn normally evaluates data, his clients are in real trouble.
I first flipped through Microtrends while at the YearlyKos convention, and Penn, astonishingly, seemed to comprehend the importance of the loosely connected, grassroots-driven, progressive movement's flowering. “I suspect the lefty boom will bring a surge in the promotion of sheer creative energy,” Penn writes, “driven by an idea that is at the heart of this book—that small groups of people, sharing common experiences, can increasingly be drawn together to rally for their interests.” I was shocked—Penn was speaking admirably of “lefties,” not trying to recast them as moderates, not trying to write them out of the party? He was endorsing open-source politics, rather than a top-down structure? I had misjudged the man!
I read on. Penn was talking about actual lefties—people who are born left-handed. Increasingly grim, I absorbed the first hard blows of Penn’s interpretative technique: “More lefties,” he enthuses, “could mean more military innovation: Famous military leaders from Charlemagne to Alexander the Great to Julius Caesar to Napoleon—as well as Colin Powell and Norman Schwarzkopf—were left-handed.” He uses the same thunderingly awful logic to argue that we’ll see more art and music greats, more famous criminals, more great comedians, more “executive greatness,” and better tennis and basketball players.
This is what statisticians—or anyone who has taken a statistics class—call a “correlation/causation error.” It is not enough to cherrypick a couple famed military leaders, notice that they're lefties and assume that something intrinsic to their handedness caused their tactical genius. It is not enough to say that past cultures discouraged left-handedness and use that as a stand-in for discouraging creativity of all sorts. To say that Bill Gates is right-handed does not suggest that a greater proportion of right-handed people would mean more Bill Gateses. For a professional pollster to imply that correlation equals causation is like a firefighter trying to put out flames by tossing a toaster into the blaze—it bespeaks a complete unfamiliarity with the relevant techniques.
