Legal scholar Cass Sunstein and behavioral economist Richard Thaler unleashed an incredibly seductive idea in 2008 with their popular book Nudge. Many of society's biggest problems, they suggested, from poor public health to environmental degradation to lousy retirement planning, could be solved without expensive interventions or intrusive regulation.
All policymakers have to do is alter the environments in which people make decisions, gently nudging them toward the choices that would improve their lives — away from the potato chips, say, or toward that corporate 401(k) match.
"To count as a nudge, the intervention must be easy and cheap to avoid," the authors wrote. "Nudges are not mandates. Putting the fruit at eye level counts as a nudge. Banning junk food does not."
As an added bonus, Sunstein and Thaler figured the concept — recognized by some as "libertarian paternalism" — ought to appeal to liberal and conservative politicians alike.
Beyond the influence of their book, Sunstein and Thaler have taken these ideas straight to government. Sunstein now heads the White House Office of Information and Regulatory Affairs (under a liberal president), and Thaler is advising conservative British Prime Minister David Cameron's cabinet through a group known cheekily as the "nudge unit."
"It's pretty popular over here," said Theresa Marteau, director of the Behavior and Health Research Unit at the University of Cambridge Institute of Public Health. "These ideas are forming really the framework for how government wants to improve population health."
And this gives her pause.
"The U.S. and the U.K. spend a lot of money on research — not enough in my view — trying to develop interventions, develop the evidence base for us to know what is more or less effective," she said. "Then here comes a new book with the promise of changing behavior through the relatively simple means of altering environments, or the context in which behavior occurs, without using bans, without using pricing."
Marteau and several of her colleagues question whether the elegant solution is really as effective as Nudge suggests (and as British and American politicians would like it to be), particularly when it comes to the vast and complex challenges of public health.
"As researchers, we're paid to be skeptical, to say, 'OK, well that's interesting. Let's now see where the evidence is,'" Marteau said. "Will this not only change behavior, but will it result in sustained change and sustained change that is large enough to be able to achieve the scale of change that's needed to have an impact on population health?"
Her conclusion after an initial review of the research: "There was remarkably little evidence to support the ideas behind nudging in the context of changing health-related behavior."
She and four colleagues expand on the critique in an analysis published this week on the website of the British Medical Journal. They're planning a more extensive review, but Marteau is skeptical that light-touch government nudges could ever be effective in a world where so many powerful "unhealthy nudges" already are in place.
Nudges clearly can be effective — advertising uses the concept to great effect, priming our automatic impulses to go grab a sweet snack or to drink the new beer everyone on TV is already swigging. So, in theory, healthy nudges could work, too. But they're up against the tide of significantly more powerful unhealthy influences backed by companies needing to sell you something.
And their nudges are just so much more appealing.
"It's much easier to nudge someone toward drinking a beer and eating a pizza and lying on a sofa than it is to nudge them toward the opposite," Marteau said. "Given the power of that, having fruit at a checkout [counter] is most unlikely to be able to compete with that in any meaningful way."
Good government health policy, she suggests, would have to tackle both the helpful nudges and the unhelpful ones (and more research is needed to determine if this is really possible and just how to do it). But curbing the lure of fat, salt and sugar certainly won't be as cost-free as suggestively planting fruit displays in your neighborhood grocery store. And nudging has come to represent shorthand for the cheap and simple solution everyone can agree on.
"This is why this idea has caught on, because it's selling a very attractive proposition," Marteau said. "It's a political philosophy rather than behavioral science."