Nudging refers to the practice of using a small, non-coercive intervention to change someone’s behavior. Some classic examples of nudges include sending reminder texts to people to do something (e.g. vote), using smaller plates during meals to reduce portion sizes, or placing fruit in grocery store checkout lines (rather than candy) to encourage healthier eating.
When nudging first rose to prominence, it was an attractive option for changing behavior because:
- Studies reported large ( ish) effect sizes; and
- It is incredibly cheap to implement, particularly when compared against larger structural or policy changes.
Since then, much of the research on nudging has been debunked. Population-scale studies have shown small effect sizes (e.g. ) when attempting to use nudges to change behavior.
The large effect sizes in some academic studies were attributed to things like publication bias, heterogeneity in effects (i.e. nudges can vary dramatically in how effective they are), and issues due to the scale of studies.
Nudges today are seen as low-cost, low-yield tools. One potential exception to this is nudges that automatically change a default behavior. For instance, nudges that automatically enroll employees in a 401(k) program are very effective in increasing retirement savings.