Politicians love nudge theory. But beware its doppelgänger “sludge”

With nudge, comes sludge
With nudge, comes sludge
Image: Reuters/ You’ve heard of nudge theory. Beware its doppleganger: “sludge”
We may earn a commission from links on this page.

Politicians around the world have been happily nudging us for at least a decade. Making pension programs opt-in by default to encourage higher enrollment rates? Nudge. Labeling rubbish bins “landfill” to increase recycling? Nudge nudge.  

“Nudge” theory describes the use of behavioral science to influence public behavior, and the approach was widely embraced after Cass Sunstein and Richard Thaler published their book Nudge in 2008. In the years since, the UK, US, Japan, the World Bank, and many others have integrated nudge behavioral economics into their policies. Thaler even won the Nobel prize in economics for his work. 

The trouble is, now that these tactics are well-known, there’s nothing to stop them being used to more dubious ends. Thaler has taken to calling misuse of nudge theory “sludge.” 

This practice, he tells Quartz, has two defining characteristics: “Friction and bad intentions.” Instead of making choices easier, as nudge does, sludge often makes them hard. And, crucially, sludge is not in the best interests of those being nudged (sludged?). Now that nudges are an increasingly standard feature of international politics, there’s little to stop politicians from more heavily leaning on behavioral economics to coerce the public. 

Corporations are notorious practitioners of sludge—just think of every newsletter and subscription that’s oh-so-easy to sign up for but incredibly difficult to cancel. But governments, too, increasingly show signs of sludge. Thaler points to US governmental efforts to make it more difficult to vote—such as Ohio’s efforts to kick people off voting rolls if they skip a few elections—as one example. 

Nudge and sludge are portrayed as opposites, but ultimately both encourage (or manipulate, depending on your perspective) the public to pursue a particular choice. And whether any one nudge is truly positive is entirely subjective. “You can never be certain [that a nudge is for good],” says Thaler. Even a pro-recycling nudge can feel scheming from the perspective of those who deny the impact of man-made climate change. One study found that people are more likely to support nudges that align with their personal politics; someone who’s socially liberal is more likely to favor nudges that encourage safe sex education in high school, for example, while someone who’s socially conservative is more likely to support nudges for high school programs on intelligent design.

As behavioral science became better known over the past decade, its methods may well have been applied to a wider spectrum of political uses. Gerry Stoker, professor of governance at the University of Cannbera and the University of Southampton, says it’s “certainly possible” that the popularization of nudge “let the genie out of the bottle.” Thaler downplays his impact, insisting that both sludge and nudge were widely practiced before his book. Though perhaps “some marketing person will read our book and get some clever idea,” he says, many nudge methods have been in play for decades. 

But while advertisers have certainly been manipulating people into buying products pre-2008, Nudge made behavioral economics not just acceptable, but positively perceived in politics. 

Which means it’s time to ensure that nudges are a political force for good. One method, says Stoker, is to make sure that politicians’ interventions do not override personal agency. “There’s nothing wrong with nudge as long as it’s still connected with choice,” he says, pointing to nudges that encourage people to attend doctors appointments they’ve made. “You can simply ignore the nudge. You don’t have to act on the back of it,” he says. Thaler agrees, noting the nudges he devised have an “easy opt out”; if someone wants to pay off student loans rather than opting into a pension scheme, for example, they can make that choice.

Thaler doesn’t have much specific advice on how to resist sludge, suggesting most of us will get used to common nefarious practices. “Keeping your antenna open is useful and learning the basic tricks [is useful],” he says. 

Here’s a freebie: It’s rarely a good idea to buy the optional travel insurance.