Sludge and Dark Patterns

In 2023, the Federal Trade Commission sued Amazon, alleging that canceling an Amazon Prime membership required navigating through four pages and multiple confusing options — a process employees reportedly nicknamed the 'Iliad Flow,' after Homer's famously long epic poem. Signing up, by contrast, took two clicks. That gap between an easy sign-up and a hard cancellation isn't an accident. It has a name: sludge.

You will learn the definition of sludge, a term coined by economists Cass Sunstein and Richard Thaler. You will learn to identify at least four common dark pattern designs used online. You will learn how sludge relates to the broader idea of a 'nudge' in behavioral economics. You will learn what regulators are doing to limit these designs.

In behavioral economics, a 'nudge' is a small design choice that makes a good decision easier — like putting fruit at eye level in a cafeteria instead of banning junk food. Richard Thaler, who won the 2017 Nobel Prize in Economics for his work on behavioral economics, and legal scholar Cass Sunstein coined the term 'sludge' in a 2020 paper to describe the opposite: friction deliberately added to make a good decision, like canceling a subscription or unenrolling from a costly plan, harder than it needs to be. Sludge doesn't have to be illegal to be effective. It simply relies on the fact that extra clicks, confusing menus, and delay tactics cause a percentage of people to give up and stay subscribed.

'Roach motel' design makes signing up effortless but makes leaving deliberately difficult, exactly like the Amazon Prime cancellation flow the FTC challenged. 'Confirmshaming' uses guilt-inducing language on an opt-out button, such as making the 'No thanks' option read 'No, I don't want to save money.' 'Drip pricing' reveals extra mandatory fees — resort fees, service charges, processing fees — only at the final checkout step, after a customer has already invested time in the purchase. 'Forced continuity' silently converts a free trial into a paid subscription without a clear reminder before the charge hits.

Sludge appears far outside e-commerce: complicated financial-aid renewal forms can cause eligible college students to lose aid, and confusing government benefit paperwork can cause eligible families to miss assistance they qualify for. Sunstein has argued that reducing sludge in public programs is itself a form of good government, since friction falls hardest on people with the least time, language access, or paperwork support to push through it.