NUDGE Theory
Nudge theory changes the default or framing of a choice, not the options or incentives themselves, so people end up choosing what actually serves them without anyone restricting what they're allowed to pick.
Same menu of choices, only the default has moved from the hard path to the easy one.
Reach for this when…
- People say they want to do something (save, recycle, enrol) and then don't.
- A form or process is technically available but almost nobody uses it.
- You want behaviour change without adding rules, fines or bans.
How to run it
- Pick one specific behaviour to change - not 'be healthier', but 'enrol in the pension plan'.
- Map the current choice architecture: what's the default, and what does it cost in effort?
- Design the nudge: change the default, simplify the choice, add social proof, or fix the timing.
- Test it against a control group before rolling it out everywhere.
- Scale only the nudges that measurably moved behaviour, drop the rest.
A worked example
Situation. Banco Confianza, a microfinance bank in Medellin, Colombia run by branch manager Camila Restrepo, offered an automatic-savings feature that almost nobody switched on.
Applied. She changed nothing about the feature itself, only the default: new customers were now enrolled automatically and had to actively opt out, and the enrolment screen added a line showing how many other customers at the branch had kept it on.
Result. Opt-in enrolment had sat under one in ten customers for two years. Under the new default, roughly nine in ten stayed enrolled, because staying was now the path of least resistance.
The catch
A nudge that works because people aren't paying attention sits uncomfortably close to exploiting inattention, and the ethics get real once you're nudging toward outcomes that benefit the business more than the customer. Effects also fade: novelty nudges lose power once people notice the pattern, and what nudges one culture barely registers in another.
If you wouldn't be comfortable explaining the nudge to the person it's aimed at, you've crossed from nudging into manipulating.
Origin: Richard Thaler and Cass Sunstein