Recent large-scale randomized experiments find that helping people form implementation intentions by asking when and where they plan to act increases one-time actions, such as vaccinations, preventative screenings and voting. We investigate the effect of a simple scalable planning intervention...

We conducted a randomized controlled trial testing the effect of modest incentives to attend the gym among new members of a fitness facility, a population that is already engaged in trying to change a health behavior. Our experiment randomized 836 new members of a private gym into a control...

The use of incentives to encourage healthy behaviors is increasingly widespread, but we have little evidence about how best to structure these programs. We explore how different incentive designs affect behavior on the extensive and intensive margins through an experiment offering incentives to...