Working Paper: NBER ID: w23567
Authors: Mariana Carrera; Heather Royer; Mark Stehr; Justin Sydnor
Abstract: 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 group, receiving a $30 payment unconditionally, or one of 3 incentive groups, receiving a payment if they attended the gym at least 9 times over their first 6 weeks as members. The incentives were a $30 payment, a $60 payment, and an item costing $30 that leveraged the endowment effect. These incentives had only moderate impacts on attendance during members’ first 6 weeks and no effect on their subsequent visit trajectories. We document substantial overconfidence among new members about their likely visit rates and discuss how overconfidence may undermine the effectiveness of a modest incentive program.
Keywords: financial incentives; gym attendance; habit formation; randomized controlled trial
JEL Codes: C93; D03; I12
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| financial incentives (M52) | gym attendance (Z29) |
| financial incentives (M52) | probability of reaching nine visits (C41) |
| financial incentives (M52) | average number of visits (Z30) |
| item incentive (M52) | gym attendance (Z29) |
| prior exercise behavior (C92) | impact of incentives on gym attendance (M52) |
| incentives (M52) | sustained gym attendance (I19) |