A nudge is a technique used by choice architects in order to change someone’s behaviour in a very easy and low-cost way, without reducing the number of choices available. We often see it described as “non-enforced compliance”.

Choice architects and policy makers aim to change people’s behaviour and alter their decisions more effectively using a nudge rather than legislation or direct enforcement. It has been described as “libertarian paternalism”.

Nudge theory is generally used to describe situations where nudges are used to improve the life and wellbeing of people and society.

"A Nudge “is any aspect of the choice architecture that alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives. To count as a mere nudge, the intervention must be easy and cheap to avoid. Nudges are not mandates. Putting fruit at eye level counts as a nudge. Banning junk food does not”. Thaler & Sunstein, 2008

A nudge is any intervention in which economic incentives are not modified