A nudge is a small, cheap change to how a choice is presented, a reminder, a default setting, a better-worded letter, meant to gently steer what people do. The real question is how much a nudge actually works. Watch one number survive a reality check.
Picture a nudge aimed at a real goal, say getting more people to pay a bill on time. In the studies that got published, nudges like this lifted the behaviour by about a third, on average. The bar shows the size of that effect.
the headline
no effectdoubles the behaviour
Published studies: about a third more
But the average hides the real story. The nudge family is lopsided. Pick one: